100561865 has 16 divisors (see below), whose sum is σ = 127526400. Its totient is φ = 75970752.

The previous prime is 100561859. The next prime is 100561871. The reversal of 100561865 is 568165001.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (100561859) and next prime (100561871).

It is a cyclic number.

It is not a de Polignac number, because 100561865 - 2⁴ = 100561849 is a prime.

It is a super-2 number, since 2×100561865² = 20225377384556450, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3551 + ... + 14619.

It is an arithmetic number, because the mean of its divisors is an integer number (7970400).

Almost surely, 2^100561865 is an apocalyptic number.

It is an amenable number.

100561865 is a deficient number, since it is larger than the sum of its proper divisors (26964535).

100561865 is a wasteful number, since it uses less digits than its factorization.

100561865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11176.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 100561865 is about 10028.0538989377. The cubic root of 100561865 is about 465.0265757347.

The spelling of 100561865 in words is "one hundred million, five hundred sixty-one thousand, eight hundred sixty-five".