21217637632 has 36 divisors (see below), whose sum is σ = 44193814560. Its totient is φ = 10147563008.

The previous prime is 21217637591. The next prime is 21217637641. The reversal of 21217637632 is 23673671212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1795882 + ... + 1807657.

It is an arithmetic number, because the mean of its divisors is an integer number (1227605960).

Almost surely, 2^21217637632 is an apocalyptic number.

It is an amenable number.

21217637632 is an abundant number, since it is smaller than the sum of its proper divisors (22976176928).

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

21217637632 is an equidigital number, since it uses as much as digits as its factorization.

21217637632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3603578 (or 3603564 counting only the distinct ones).

The product of its digits is 127008, while the sum is 40.

The spelling of 21217637632 in words is "twenty-one billion, two hundred seventeen million, six hundred thirty-seven thousand, six hundred thirty-two".