21218365657336 has 32 divisors (see below), whose sum is σ = 39897038592000. Its totient is φ = 10579196424160.

The previous prime is 21218365657327. The next prime is 21218365657337. The reversal of 21218365657336 is 63375656381212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21218365657337) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1570101 + ... + 6700891.

It is an arithmetic number, because the mean of its divisors is an integer number (1246782456000).

Almost surely, 2^{21218365657336} is an apocalyptic number.

It is an amenable number.

21218365657336 is a deficient number, since it is larger than the sum of its proper divisors (18678672934664).

21218365657336 is a wasteful number, since it uses less digits than its factorization.

21218365657336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5132259 (or 5132255 counting only the distinct ones).

The product of its digits is 32659200, while the sum is 58.

The spelling of 21218365657336 in words is "twenty-one trillion, two hundred eighteen billion, three hundred sixty-five million, six hundred fifty-seven thousand, three hundred thirty-six".