55645440 has 144 divisors (see below), whose sum is σ = 182390208. Its totient is φ = 14450688.

The previous prime is 55645439. The next prime is 55645451. The reversal of 55645440 is 4454655.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 164952 + ... + 165288.

Almost surely, 2^55645440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55645440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91195104).

55645440 is an abundant number, since it is smaller than the sum of its proper divisors (126744768).

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

55645440 is a wasteful number, since it uses less digits than its factorization.

55645440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 33.

The square root of 55645440 is about 7459.5871199417. The cubic root of 55645440 is about 381.7770873109. Note that the first 3 decimals are identical.

The spelling of 55645440 in words is "fifty-five million, six hundred forty-five thousand, four hundred forty".