13155520561 has 32 divisors (see below), whose sum is σ = 14453637120. Its totient is φ = 11927865600.

The previous prime is 13155520537. The next prime is 13155520643. The reversal of 13155520561 is 16502555131.

It is a de Polignac number, because none of the positive numbers 2^k-13155520561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13155520361) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 37911990 + ... + 37912336.

It is an arithmetic number, because the mean of its divisors is an integer number (451676160).

Almost surely, 2^13155520561 is an apocalyptic number.

It is an amenable number.

13155520561 is a deficient number, since it is larger than the sum of its proper divisors (1298116559).

13155520561 is a wasteful number, since it uses less digits than its factorization.

13155520561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 925.

The product of its (nonzero) digits is 22500, while the sum is 34.

The spelling of 13155520561 in words is "thirteen billion, one hundred fifty-five million, five hundred twenty thousand, five hundred sixty-one".