55181971 has 4 divisors (see below), whose sum is σ = 59426752. Its totient is φ = 50937192.

The previous prime is 55181939. The next prime is 55181999. The reversal of 55181971 is 17918155.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 55181971 - 2⁵ = 55181939 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55181971.

It is not an unprimeable number, because it can be changed into a prime (55181921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2122371 + ... + 2122396.

It is an arithmetic number, because the mean of its divisors is an integer number (14856688).

Almost surely, 2^55181971 is an apocalyptic number.

55181971 is a deficient number, since it is larger than the sum of its proper divisors (4244781).

55181971 is a wasteful number, since it uses less digits than its factorization.

55181971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4244780.

The product of its digits is 12600, while the sum is 37.

The square root of 55181971 is about 7428.4568384019. The cubic root of 55181971 is about 380.7141947166.

The spelling of 55181971 in words is "fifty-five million, one hundred eighty-one thousand, nine hundred seventy-one".