20530197765 has 128 divisors (see below), whose sum is σ = 46146723840. Its totient is φ = 8411558400.

The previous prime is 20530197763. The next prime is 20530197769. The reversal of 20530197765 is 56779103502.

20530197765 is a `hidden beast` number, since 20 + 530 + 1 + 97 + 7 + 6 + 5 = 666.

It is not a de Polignac number, because 20530197765 - 2¹ = 20530197763 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 20530197765.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20530197763) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 724137 + ... + 751953.

It is an arithmetic number, because the mean of its divisors is an integer number (360521280).

Almost surely, 2^20530197765 is an apocalyptic number.

It is an amenable number.

20530197765 is an abundant number, since it is smaller than the sum of its proper divisors (25616526075).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20530197765 is a wasteful number, since it uses less digits than its factorization.

20530197765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27920 (or 27914 counting only the distinct ones).

The product of its (nonzero) digits is 396900, while the sum is 45.

The spelling of 20530197765 in words is "twenty billion, five hundred thirty million, one hundred ninety-seven thousand, seven hundred sixty-five".