115661121111566 has 16 divisors (see below), whose sum is σ = 175210678775808. Its totient is φ = 57257569740000.

The previous prime is 115661121111553. The next prime is 115661121111577. The reversal of 115661121111566 is 665111121166511.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27182516 + ... + 31148216.

It is an arithmetic number, because the mean of its divisors is an integer number (10950667423488).

Almost surely, 2^{115661121111566} is an apocalyptic number.

115661121111566 is a deficient number, since it is larger than the sum of its proper divisors (59549557664242).

115661121111566 is a wasteful number, since it uses less digits than its factorization.

115661121111566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4110187.

The product of its digits is 64800, while the sum is 44.

Subtracting 115661121111566 from its reverse (665111121166511), we obtain a palindrome (549450000054945).

The spelling of 115661121111566 in words is "one hundred fifteen trillion, six hundred sixty-one billion, one hundred twenty-one million, one hundred eleven thousand, five hundred sixty-six".