55388731 has 4 divisors (see below), whose sum is σ = 55413864. Its totient is φ = 55363600.

The previous prime is 55388719. The next prime is 55388777. The reversal of 55388731 is 13788355.

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 55388731 - 2⁷ = 55388603 is a prime.

It is a super-2 number, since 2×55388731² = 6135823043580722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55388791) 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, 8905 + ... + 13786.

It is an arithmetic number, because the mean of its divisors is an integer number (13853466).

Almost surely, 2^55388731 is an apocalyptic number.

55388731 is a deficient number, since it is larger than the sum of its proper divisors (25133).

55388731 is a wasteful number, since it uses less digits than its factorization.

55388731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25132.

The product of its digits is 100800, while the sum is 40.

The square root of 55388731 is about 7442.3605798161. The cubic root of 55388731 is about 381.1890983612.

The spelling of 55388731 in words is "fifty-five million, three hundred eighty-eight thousand, seven hundred thirty-one".