109851561 has 12 divisors (see below), whose sum is σ = 159817840. Its totient is φ = 72706680.

The previous prime is 109851503. The next prime is 109851583. The reversal of 109851561 is 165158901.

109851561 is a `hidden beast` number, since 1 + 0 + 98 + 5 + 1 + 561 = 666.

It is not a de Polignac number, because 109851561 - 2²⁶ = 42742697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (109851061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42655 + ... + 45156.

Almost surely, 2^109851561 is an apocalyptic number.

It is an amenable number.

109851561 is a deficient number, since it is larger than the sum of its proper divisors (49966279).

109851561 is a wasteful number, since it uses less digits than its factorization.

109851561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87956 (or 87953 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 36.

The square root of 109851561 is about 10481.0095410700. The cubic root of 109851561 is about 478.9263633621.

The spelling of 109851561 in words is "one hundred nine million, eight hundred fifty-one thousand, five hundred sixty-one".