620663781 has 8 divisors (see below), whose sum is σ = 847736064. Its totient is φ = 403683680.

The previous prime is 620663779. The next prime is 620663807. The reversal of 620663781 is 187366026.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 620663781 - 2¹ = 620663779 is a prime.

It is a super-2 number, since 2×620663781² = 770447058090431922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620663711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2522901 + ... + 2523146.

It is an arithmetic number, because the mean of its divisors is an integer number (105967008).

Almost surely, 2^620663781 is an apocalyptic number.

It is an amenable number.

620663781 is a deficient number, since it is larger than the sum of its proper divisors (227072283).

620663781 is a wasteful number, since it uses less digits than its factorization.

620663781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5046091.

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 620663781 is about 24913.1246735531. The cubic root of 620663781 is about 853.0060948050.

The spelling of 620663781 in words is "six hundred twenty million, six hundred sixty-three thousand, seven hundred eighty-one".