55138944 has 128 divisors (see below), whose sum is σ = 170282880. Its totient is φ = 15482880.

The previous prime is 55138913. The next prime is 55138957. The reversal of 55138944 is 44983155.

It is a tau number, because it is divible by the number of its divisors (128).

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, 196084 + ... + 196364.

It is an arithmetic number, because the mean of its divisors is an integer number (1330335).

Almost surely, 2^55138944 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 55138944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85141440).

55138944 is an abundant number, since it is smaller than the sum of its proper divisors (115143936).

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

55138944 is a wasteful number, since it uses less digits than its factorization.

55138944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378 (or 366 counting only the distinct ones).

The product of its digits is 86400, while the sum is 39.

The square root of 55138944 is about 7425.5601808887. The cubic root of 55138944 is about 380.6152176487.

The spelling of 55138944 in words is "fifty-five million, one hundred thirty-eight thousand, nine hundred forty-four".