21507871170 has 128 divisors (see below), whose sum is σ = 54771344640. Its totient is φ = 5396751360.

The previous prime is 21507871139. The next prime is 21507871211. The reversal of 21507871170 is 7117870512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7237785 + ... + 7240755.

It is an arithmetic number, because the mean of its divisors is an integer number (427901130).

Almost surely, 2^21507871170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21507871170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27385672320).

21507871170 is an abundant number, since it is smaller than the sum of its proper divisors (33263473470).

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

21507871170 is a wasteful number, since it uses less digits than its factorization.

21507871170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3220.

The product of its (nonzero) digits is 27440, while the sum is 39.

The spelling of 21507871170 in words is "twenty-one billion, five hundred seven million, eight hundred seventy-one thousand, one hundred seventy".