118591561 has 16 divisors (see below), whose sum is σ = 131788800. Its totient is φ = 105814800.

The previous prime is 118591553. The next prime is 118591567. The reversal of 118591561 is 165195811.

118591561 = T₄₆₃₈ + T₄₆₃₉ + ... + T₄₆₄₈.

It is a cyclic number.

It is not a de Polignac number, because 118591561 - 2³ = 118591553 is a prime.

Its product of digits (10800) is a multiple of the sum of its prime divisors (900).

It is a self number, because there is not a number n which added to its sum of digits gives 118591561.

It is not an unprimeable number, because it can be changed into a prime (118591567) 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, 207406 + ... + 207976.

It is an arithmetic number, because the mean of its divisors is an integer number (8236800).

Almost surely, 2^118591561 is an apocalyptic number.

118591561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

118591561 is a deficient number, since it is larger than the sum of its proper divisors (13197239).

118591561 is a wasteful number, since it uses less digits than its factorization.

118591561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900.

The product of its digits is 10800, while the sum is 37.

The square root of 118591561 is about 10889.9752524971. The cubic root of 118591561 is about 491.3050881468.

The spelling of 118591561 in words is "one hundred eighteen million, five hundred ninety-one thousand, five hundred sixty-one".