21591263580 has 48 divisors (see below), whose sum is σ = 61480218240. Its totient is φ = 5660081728.

The previous prime is 21591263579. The next prime is 21591263581. The reversal of 21591263580 is 8536219512.

It is an interprime number because it is at equal distance from previous prime (21591263579) and next prime (21591263581).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21591263581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3046074 + ... + 3053153.

It is an arithmetic number, because the mean of its divisors is an integer number (1280837880).

Almost surely, 2^21591263580 is an apocalyptic number.

21591263580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21591263580 is an abundant number, since it is smaller than the sum of its proper divisors (39888954660).

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

21591263580 is a wasteful number, since it uses less digits than its factorization.

21591263580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6099298 (or 6099296 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 42.

The spelling of 21591263580 in words is "twenty-one billion, five hundred ninety-one million, two hundred sixty-three thousand, five hundred eighty".