55138140 has 144 divisors (see below), whose sum is σ = 182250432. Its totient is φ = 13436928.

The previous prime is 55138117. The next prime is 55138151. The reversal of 55138140 is 4183155.

55138140 is a `hidden beast` number, since 5 + 513 + 8 + 140 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 112977 + ... + 113463.

It is an arithmetic number, because the mean of its divisors is an integer number (1265628).

Almost surely, 2^55138140 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 55138140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91125216).

55138140 is an abundant number, since it is smaller than the sum of its proper divisors (127112292).

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

55138140 is a wasteful number, since it uses less digits than its factorization.

55138140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556 (or 551 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 55138140 is about 7425.5060433616. The cubic root of 55138140 is about 380.6133676790.

It can be divided in two parts, 55138 and 140, that added together give a triangular number (55278 = T₃₃₂).

The spelling of 55138140 in words is "fifty-five million, one hundred thirty-eight thousand, one hundred forty".