20565156500 has 96 divisors (see below), whose sum is σ = 51373271040. Its totient is φ = 7045056000.

The previous prime is 20565156499. The next prime is 20565156527. The reversal of 20565156500 is 565156502.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7562141 + ... + 7564859.

It is an arithmetic number, because the mean of its divisors is an integer number (535138240).

Almost surely, 2^20565156500 is an apocalyptic number.

20565156500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20565156500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25686635520).

20565156500 is an abundant number, since it is smaller than the sum of its proper divisors (30808114540).

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

20565156500 is a wasteful number, since it uses less digits than its factorization.

20565156500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4906 (or 4894 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 35.

The spelling of 20565156500 in words is "twenty billion, five hundred sixty-five million, one hundred fifty-six thousand, five hundred".