11566100721 has 16 divisors (see below), whose sum is σ = 17666611200. Its totient is φ = 6593421648.

The previous prime is 11566100657. The next prime is 11566100743. The reversal of 11566100721 is 12700166511.

It is not a de Polignac number, because 11566100721 - 2⁶ = 11566100657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11566100621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 648441 + ... + 666038.

It is an arithmetic number, because the mean of its divisors is an integer number (1104163200).

Almost surely, 2^11566100721 is an apocalyptic number.

It is an amenable number.

11566100721 is a deficient number, since it is larger than the sum of its proper divisors (6100510479).

11566100721 is a wasteful number, since it uses less digits than its factorization.

11566100721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1314908.

The product of its (nonzero) digits is 2520, while the sum is 30.

The spelling of 11566100721 in words is "eleven billion, five hundred sixty-six million, one hundred thousand, seven hundred twenty-one".