55390728 has 32 divisors (see below), whose sum is σ = 138744000. Its totient is φ = 18427968.

The previous prime is 55390697. The next prime is 55390759. The reversal of 55390728 is 82709355.

It is an interprime number because it is at equal distance from previous prime (55390697) and next prime (55390759).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12450 + ... + 16302.

It is an arithmetic number, because the mean of its divisors is an integer number (4335750).

Almost surely, 2^55390728 is an apocalyptic number.

It is an amenable number.

55390728 is an abundant number, since it is smaller than the sum of its proper divisors (83353272).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55390728 is a wasteful number, since it uses less digits than its factorization.

55390728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4461 (or 4457 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 39.

The square root of 55390728 is about 7442.4947430280. The cubic root of 55390728 is about 381.1936794704.

The spelling of 55390728 in words is "fifty-five million, three hundred ninety thousand, seven hundred twenty-eight".