20001511565 has 32 divisors (see below), whose sum is σ = 29198880000. Its totient is φ = 12847431168.

The previous prime is 20001511549. The next prime is 20001511573. The reversal of 20001511565 is 56511510002.

It is a cyclic number.

It is not a de Polignac number, because 20001511565 - 2⁴ = 20001511549 is a prime.

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, 109790 + ... + 228159.

It is an arithmetic number, because the mean of its divisors is an integer number (912465000).

Almost surely, 2^20001511565 is an apocalyptic number.

It is an amenable number.

20001511565 is a deficient number, since it is larger than the sum of its proper divisors (9197368435).

20001511565 is a wasteful number, since it uses less digits than its factorization.

20001511565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338069.

The product of its (nonzero) digits is 1500, while the sum is 26.

The spelling of 20001511565 in words is "twenty billion, one million, five hundred eleven thousand, five hundred sixty-five".