54231991 has 4 divisors (see below), whose sum is σ = 59162184. Its totient is φ = 49301800.

The previous prime is 54231949. The next prime is 54232007. The reversal of 54231991 is 19913245.

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 54231991 - 2²³ = 45843383 is a prime.

It is a super-2 number, since 2×54231991² = 5882217695648162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (54231911) 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, 2465080 + ... + 2465101.

It is an arithmetic number, because the mean of its divisors is an integer number (14790546).

Almost surely, 2^54231991 is an apocalyptic number.

54231991 is a deficient number, since it is larger than the sum of its proper divisors (4930193).

54231991 is a wasteful number, since it uses less digits than its factorization.

54231991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4930192.

The product of its digits is 9720, while the sum is 34.

The square root of 54231991 is about 7364.2372992727. The cubic root of 54231991 is about 378.5168200945.

The spelling of 54231991 in words is "fifty-four million, two hundred thirty-one thousand, nine hundred ninety-one".