21591026160 has 320 divisors, whose sum is σ = 74710646784. Its totient is φ = 5114188800.

The previous prime is 21591026131. The next prime is 21591026161. The reversal of 21591026160 is 6162019512.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21591026161) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23804427 + ... + 23805333.

Almost surely, 2^21591026160 is an apocalyptic number.

21591026160 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 21591026160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37355323392).

21591026160 is an abundant number, since it is smaller than the sum of its proper divisors (53119620624).

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

21591026160 is a wasteful number, since it uses less digits than its factorization.

21591026160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132 (or 1126 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 33.

The spelling of 21591026160 in words is "twenty-one billion, five hundred ninety-one million, twenty-six thousand, one hundred sixty".