1620568881 has 12 divisors (see below), whose sum is σ = 2464023120. Its totient is φ = 1023517080.

The previous prime is 1620568879. The next prime is 1620568903. The reversal of 1620568881 is 1888650261.

1620568881 is a `hidden beast` number, since 1 + 6 + 2 + 0 + 568 + 8 + 81 = 666.

1620568881 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1620568881 - 2¹ = 1620568879 is a prime.

It is a super-2 number, since 2×1620568881² = 5252486996131184322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1620568801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4738335 + ... + 4738676.

It is an arithmetic number, because the mean of its divisors is an integer number (205335260).

Almost surely, 2^1620568881 is an apocalyptic number.

It is an amenable number.

1620568881 is a deficient number, since it is larger than the sum of its proper divisors (843454239).

1620568881 is a wasteful number, since it uses less digits than its factorization.

1620568881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9477036 (or 9477033 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 45.

The square root of 1620568881 is about 40256.2899557324. The cubic root of 1620568881 is about 1174.5977511889.

The spelling of 1620568881 in words is "one billion, six hundred twenty million, five hundred sixty-eight thousand, eight hundred eighty-one".