21158020518180 has 1536 divisors, whose sum is σ = 78518174515200. Its totient is φ = 4138573824000.

The previous prime is 21158020518169. The next prime is 21158020518191. The reversal of 21158020518180 is 8181502085112.

It is an interprime number because it is at equal distance from previous prime (21158020518169) and next prime (21158020518191).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 129803806779 + ... + 129803806941.

It is an arithmetic number, because the mean of its divisors is an integer number (51118603200).

Almost surely, 2^{21158020518180} is an apocalyptic number.

21158020518180 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 21158020518180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39259087257600).

21158020518180 is an abundant number, since it is smaller than the sum of its proper divisors (57360153997020).

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

21158020518180 is a wasteful number, since it uses less digits than its factorization.

21158020518180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525 (or 523 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 42.

The spelling of 21158020518180 in words is "twenty-one trillion, one hundred fifty-eight billion, twenty million, five hundred eighteen thousand, one hundred eighty".