20515561365 has 32 divisors (see below), whose sum is σ = 35444787840. Its totient is φ = 10072855296.

The previous prime is 20515561357. The next prime is 20515561441. The reversal of 20515561365 is 56316551502.

It is not a de Polignac number, because 20515561365 - 2³ = 20515561357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68295 + ... + 213764.

It is an arithmetic number, because the mean of its divisors is an integer number (1107649620).

Almost surely, 2^20515561365 is an apocalyptic number.

It is an amenable number.

20515561365 is a deficient number, since it is larger than the sum of its proper divisors (14929226475).

20515561365 is a wasteful number, since it uses less digits than its factorization.

20515561365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282453.

The product of its (nonzero) digits is 135000, while the sum is 39.

The spelling of 20515561365 in words is "twenty billion, five hundred fifteen million, five hundred sixty-one thousand, three hundred sixty-five".