20865777597 has 12 divisors (see below), whose sum is σ = 34445093280. Its totient is φ = 11923301448.

The previous prime is 20865777497. The next prime is 20865777623. The reversal of 20865777597 is 79577756802.

20865777597 is a `hidden beast` number, since 2 + 0 + 8 + 6 + 577 + 7 + 59 + 7 = 666.

It is not a de Polignac number, because 20865777597 - 2¹⁵ = 20865744829 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63), and also a Moran number because the ratio is a prime number: 331202819 = 20865777597 / (2 + 0 + 8 + 6 + 5 + 7 + 7 + 7 + 5 + 9 + 7).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20865777397) 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, 165601347 + ... + 165601472.

It is an arithmetic number, because the mean of its divisors is an integer number (2870424440).

Almost surely, 2^20865777597 is an apocalyptic number.

It is an amenable number.

20865777597 is a deficient number, since it is larger than the sum of its proper divisors (13579315683).

20865777597 is a wasteful number, since it uses less digits than its factorization.

20865777597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331202832 (or 331202829 counting only the distinct ones).

The product of its (nonzero) digits is 51861600, while the sum is 63.

The spelling of 20865777597 in words is "twenty billion, eight hundred sixty-five million, seven hundred seventy-seven thousand, five hundred ninety-seven".