55991761 has 12 divisors (see below), whose sum is σ = 68965668. Its totient is φ = 45169152.

The previous prime is 55991753. The next prime is 55991777. The reversal of 55991761 is 16719955.

It can be written as a sum of positive squares in 2 ways, for example, as 47348161 + 8643600 = 6881^2 + 2940^2 .

It is not a de Polignac number, because 55991761 - 2³ = 55991753 is a prime.

It is a super-2 number, since 2×55991761² = 6270154599762242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55991701) 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, 32776 + ... + 34441.

It is an arithmetic number, because the mean of its divisors is an integer number (5747139).

Almost surely, 2^55991761 is an apocalyptic number.

It is an amenable number.

55991761 is a deficient number, since it is larger than the sum of its proper divisors (12973907).

55991761 is a wasteful number, since it uses less digits than its factorization.

55991761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67248 (or 67241 counting only the distinct ones).

The product of its digits is 85050, while the sum is 43.

The square root of 55991761 is about 7482.7642619556. The cubic root of 55991761 is about 382.5674729676.

The spelling of 55991761 in words is "fifty-five million, nine hundred ninety-one thousand, seven hundred sixty-one".