109257561 has 12 divisors (see below), whose sum is σ = 180361792. Its totient is φ = 62432856.

The previous prime is 109257541. The next prime is 109257607. The reversal of 109257561 is 165752901.

109257561 is a `hidden beast` number, since 1 + 0 + 92 + 5 + 7 + 561 = 666.

It is not a de Polignac number, because 109257561 - 2¹¹ = 109255513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (109257541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 867061 + ... + 867186.

Almost surely, 2^109257561 is an apocalyptic number.

It is an amenable number.

109257561 is a deficient number, since it is larger than the sum of its proper divisors (71104231).

109257561 is a wasteful number, since it uses less digits than its factorization.

109257561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1734260 (or 1734257 counting only the distinct ones).

The product of its (nonzero) digits is 18900, while the sum is 36.

The square root of 109257561 is about 10452.6341656063. The cubic root of 109257561 is about 478.0615704143.

It can be divided in two parts, 1092 and 57561, that added together give a triangular number (58653 = T₃₄₂).

The spelling of 109257561 in words is "one hundred nine million, two hundred fifty-seven thousand, five hundred sixty-one".