2155620178800 has 900 divisors, whose sum is σ = 8778393160768. Its totient is φ = 505688832000.

The previous prime is 2155620178793. The next prime is 2155620178883. The reversal of 2155620178800 is 88710265512.

2155620178800 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 620 + 17 + 8 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (900).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 121523532 + ... + 121541268.

Almost surely, 2^{2155620178800} is an apocalyptic number.

2155620178800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2155620178800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4389196580384).

2155620178800 is an abundant number, since it is smaller than the sum of its proper divisors (6622772981968).

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

2155620178800 is a wasteful number, since it uses less digits than its factorization.

2155620178800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17820 (or 17789 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 45.

The spelling of 2155620178800 in words is "two trillion, one hundred fifty-five billion, six hundred twenty million, one hundred seventy-eight thousand, eight hundred".