55643440 has 40 divisors (see below), whose sum is σ = 135000288. Its totient is φ = 21288960.

The previous prime is 55643387. The next prime is 55643453. The reversal of 55643440 is 4434655.

It is a tau number, because it is divible by the number of its divisors (40).

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, 13281 + ... + 16960.

Almost surely, 2^55643440 is an apocalyptic number.

It is an amenable number.

55643440 is an abundant number, since it is smaller than the sum of its proper divisors (79356848).

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

55643440 is a wasteful number, since it uses less digits than its factorization.

55643440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30277 (or 30271 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 31.

The square root of 55643440 is about 7459.4530630603. The cubic root of 55643440 is about 381.7725133313.

The spelling of 55643440 in words is "fifty-five million, six hundred forty-three thousand, four hundred forty".