55811961 has 12 divisors (see below), whose sum is σ = 84122688. Its totient is φ = 35590104.

The previous prime is 55811953. The next prime is 55811981. The reversal of 55811961 is 16911855.

55811961 is a `hidden beast` number, since 5 + 581 + 19 + 61 = 666.

It is not a de Polignac number, because 55811961 - 2³ = 55811953 is a prime.

It is a super-2 number, since 2×55811961² = 6229949981331042, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (55811941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 134605 + ... + 135018.

It is an arithmetic number, because the mean of its divisors is an integer number (7010224).

Almost surely, 2^55811961 is an apocalyptic number.

It is an amenable number.

55811961 is a deficient number, since it is larger than the sum of its proper divisors (28310727).

55811961 is a wasteful number, since it uses less digits than its factorization.

55811961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269652 (or 269649 counting only the distinct ones).

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

The square root of 55811961 is about 7470.7403247603. The cubic root of 55811961 is about 382.1575353275.

The spelling of 55811961 in words is "fifty-five million, eight hundred eleven thousand, nine hundred sixty-one".