55187315820 has 384 divisors, whose sum is σ = 212953466880. Its totient is φ = 11553684480.

The previous prime is 55187315819. The next prime is 55187315831. The reversal of 55187315820 is 2851378155.

55187315820 is a `hidden beast` number, since 55 + 18 + 7 + 3 + 1 + 582 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6433054 + ... + 6441626.

It is an arithmetic number, because the mean of its divisors is an integer number (554566320).

Almost surely, 2^55187315820 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 55187315820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106476733440).

55187315820 is an abundant number, since it is smaller than the sum of its proper divisors (157766151060).

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

55187315820 is a wasteful number, since it uses less digits than its factorization.

55187315820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8742 (or 8734 counting only the distinct ones).

The product of its (nonzero) digits is 336000, while the sum is 45.

The spelling of 55187315820 in words is "fifty-five billion, one hundred eighty-seven million, three hundred fifteen thousand, eight hundred twenty".