21235427580 has 96 divisors (see below), whose sum is σ = 62624669184. Its totient is φ = 5365913344.

The previous prime is 21235427531. The next prime is 21235427581. The reversal of 21235427580 is 8572453212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21235427581) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 75754 + ... + 219566.

It is an arithmetic number, because the mean of its divisors is an integer number (652340304).

Almost surely, 2^21235427580 is an apocalyptic number.

21235427580 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 21235427580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31312334592).

21235427580 is an abundant number, since it is smaller than the sum of its proper divisors (41389241604).

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

21235427580 is a wasteful number, since it uses less digits than its factorization.

21235427580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143955 (or 143953 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 39.

The spelling of 21235427580 in words is "twenty-one billion, two hundred thirty-five million, four hundred twenty-seven thousand, five hundred eighty".