620988507568881 has 45 divisors (see below), whose sum is σ = 931595724541713. Its totient is φ = 412238643563520.

The previous prime is 620988507568879. The next prime is 620988507568901. The reversal of 620988507568881 is 188865705889026.

The square root of 620988507568881 is 24919641.

It is a perfect power (a square), and thus also a powerful number.

620988507568881 is a `hidden beast` number, since 6 + 20 + 9 + 8 + 8 + 507 + 5 + 6 + 8 + 8 + 81 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 488378743281 + 620500128825600 = 698841^2 + 24909840^2 .

It is not a de Polignac number, because 620988507568881 - 2¹ = 620988507568879 is a prime.

It is a super-2 number, since 2×620988507568881² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 620988507568881.

It is not an unprimeable number, because it can be changed into a prime (620988507568841) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 54050695585 + ... + 54050707073.

Almost surely, 2^{620988507568881} is an apocalyptic number.

620988507568881 is the 24919641-st square number.

620988507568881 is the 12459821-st centered octagonal number.

It is an amenable number.

620988507568881 is a deficient number, since it is larger than the sum of its proper divisors (310607216972832).

620988507568881 is an frugal number, since it uses more digits than its factorization.

620988507568881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23472 (or 11733 counting only the distinct ones).

The product of its (nonzero) digits is 3715891200, while the sum is 81.

620988507568881 divided by its sum of digits (81) gives a square (7666524784801 = 2768849²).

The spelling of 620988507568881 in words is "six hundred twenty trillion, nine hundred eighty-eight billion, five hundred seven million, five hundred sixty-eight thousand, eight hundred eighty-one".