21737017220 has 24 divisors (see below), whose sum is σ = 45667914264. Its totient is φ = 8690963456.

The previous prime is 21737017219. The next prime is 21737017249. The reversal of 21737017220 is 2271073712.

It can be written as a sum of positive squares in 4 ways, for example, as 13357811776 + 8379205444 = 115576^2 + 91538^2 .

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, 193619 + ... + 284538.

It is an arithmetic number, because the mean of its divisors is an integer number (1902829761).

Almost surely, 2^21737017220 is an apocalyptic number.

21737017220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21737017220 is an abundant number, since it is smaller than the sum of its proper divisors (23930897044).

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

21737017220 is a wasteful number, since it uses less digits than its factorization.

21737017220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480439 (or 480437 counting only the distinct ones).

The product of its (nonzero) digits is 8232, while the sum is 32.

The spelling of 21737017220 in words is "twenty-one billion, seven hundred thirty-seven million, seventeen thousand, two hundred twenty".