21315522220 has 24 divisors (see below), whose sum is σ = 45158730624. Its totient is φ = 8450754816.

The previous prime is 21315522211. The next prime is 21315522257. The reversal of 21315522220 is 2222551312.

It is a super-2 number, since 2×21315522220² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4713564 + ... + 4718083.

It is an arithmetic number, because the mean of its divisors is an integer number (1881613776).

Almost surely, 2^21315522220 is an apocalyptic number.

21315522220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21315522220 is an abundant number, since it is smaller than the sum of its proper divisors (23843208404).

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

21315522220 is a wasteful number, since it uses less digits than its factorization.

21315522220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9431769 (or 9431767 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The spelling of 21315522220 in words is "twenty-one billion, three hundred fifteen million, five hundred twenty-two thousand, two hundred twenty".