55917891 has 16 divisors (see below), whose sum is σ = 84863520. Its totient is φ = 36368640.

The previous prime is 55917889. The next prime is 55917923. The reversal of 55917891 is 19871955.

55917891 is a `hidden beast` number, since 559 + 1 + 7 + 8 + 91 = 666.

It is not a de Polignac number, because 55917891 - 2¹ = 55917889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55917391) 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, 24150 + ... + 26363.

It is an arithmetic number, because the mean of its divisors is an integer number (5303970).

Almost surely, 2^55917891 is an apocalyptic number.

55917891 is a deficient number, since it is larger than the sum of its proper divisors (28945629).

55917891 is a wasteful number, since it uses less digits than its factorization.

55917891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50563 (or 50557 counting only the distinct ones).

The product of its digits is 113400, while the sum is 45.

The square root of 55917891 is about 7477.8266227561. The cubic root of 55917891 is about 382.3991583455.

The spelling of 55917891 in words is "fifty-five million, nine hundred seventeen thousand, eight hundred ninety-one".