55517978880 has 1152 divisors, whose sum is σ = 246143385600. Its totient is φ = 11537842176.

The previous prime is 55517978863. The next prime is 55517978897. The reversal of 55517978880 is 8887971555.

55517978880 is a `hidden beast` number, since 5 + 551 + 7 + 9 + 78 + 8 + 8 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (55517978863) and next prime (55517978897).

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (63).

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, 399409851 + ... + 399409989.

Almost surely, 2^55517978880 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 55517978880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123071692800).

55517978880 is an abundant number, since it is smaller than the sum of its proper divisors (190625406720).

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

55517978880 is a wasteful number, since it uses less digits than its factorization.

55517978880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316 (or 296 counting only the distinct ones).

The product of its (nonzero) digits is 28224000, while the sum is 63.

The spelling of 55517978880 in words is "fifty-five billion, five hundred seventeen million, nine hundred seventy-eight thousand, eight hundred eighty".