55138780 has 12 divisors (see below), whose sum is σ = 115791480. Its totient is φ = 22055504.

The previous prime is 55138763. The next prime is 55138799. The reversal of 55138780 is 8783155.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1378450 + ... + 1378489.

It is an arithmetic number, because the mean of its divisors is an integer number (9649290).

Almost surely, 2^55138780 is an apocalyptic number.

It is an amenable number.

55138780 is an abundant number, since it is smaller than the sum of its proper divisors (60652700).

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

55138780 is a wasteful number, since it uses less digits than its factorization.

55138780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2756948 (or 2756946 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 37.

The square root of 55138780 is about 7425.5491379426. The cubic root of 55138780 is about 380.6148402931.

The spelling of 55138780 in words is "fifty-five million, one hundred thirty-eight thousand, seven hundred eighty".