61595991 has 16 divisors (see below), whose sum is σ = 93196800. Its totient is φ = 40189464.

The previous prime is 61595987. The next prime is 61595993. The reversal of 61595991 is 19959516.

It is a happy number.

61595991 is a `hidden beast` number, since 6 + 1 + 59 + 599 + 1 = 666.

It is not a de Polignac number, because 61595991 - 2² = 61595987 is a prime.

It is a super-2 number, since 2×61595991² = 7588132214544162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61595993) 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, 23001 + ... + 25538.

It is an arithmetic number, because the mean of its divisors is an integer number (5824800).

Almost surely, 2^61595991 is an apocalyptic number.

61595991 is a deficient number, since it is larger than the sum of its proper divisors (31600809).

61595991 is a wasteful number, since it uses less digits than its factorization.

61595991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48595 (or 48589 counting only the distinct ones).

The product of its digits is 109350, while the sum is 45.

The square root of 61595991 is about 7848.3113470351. The cubic root of 61595991 is about 394.9275966209.

The spelling of 61595991 in words is "sixty-one million, five hundred ninety-five thousand, nine hundred ninety-one".