111564055661 has 4 divisors (see below), whose sum is σ = 111565432992. Its totient is φ = 111562678332.

The previous prime is 111564055643. The next prime is 111564055679. The reversal of 111564055661 is 166550465111.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166550465111 = 17 ⋅9797086183.

It is an interprime number because it is at equal distance from previous prime (111564055643) and next prime (111564055679).

It is a cyclic number.

It is not a de Polignac number, because 111564055661 - 2¹⁴ = 111564039277 is a prime.

It is a super-2 number, since 2×111564055661² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111564055601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 559031 + ... + 731876.

It is an arithmetic number, because the mean of its divisors is an integer number (27891358248).

Almost surely, 2^111564055661 is an apocalyptic number.

It is an amenable number.

111564055661 is a deficient number, since it is larger than the sum of its proper divisors (1377331).

111564055661 is an equidigital number, since it uses as much as digits as its factorization.

111564055661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1377330.

The product of its (nonzero) digits is 108000, while the sum is 41.

The spelling of 111564055661 in words is "one hundred eleven billion, five hundred sixty-four million, fifty-five thousand, six hundred sixty-one".