21021608460 has 48 divisors (see below), whose sum is σ = 60451334496. Its totient is φ = 5454254592.

The previous prime is 21021608459. The next prime is 21021608477. The reversal of 21021608460 is 6480612012.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4732377 + ... + 4736816.

It is an arithmetic number, because the mean of its divisors is an integer number (1259402802).

Almost surely, 2^21021608460 is an apocalyptic number.

21021608460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021608460 is an abundant number, since it is smaller than the sum of its proper divisors (39429726036).

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

21021608460 is a wasteful number, since it uses less digits than its factorization.

21021608460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9469242 (or 9469240 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The spelling of 21021608460 in words is "twenty-one billion, twenty-one million, six hundred eight thousand, four hundred sixty".