918744636221 has 16 divisors (see below), whose sum is σ = 944974123200. Its totient is φ = 892883816448.

The previous prime is 918744636217. The next prime is 918744636239. The reversal of 918744636221 is 122636447819.

It is a cyclic number.

It is not a de Polignac number, because 918744636221 - 2² = 918744636217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (918744536221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2249750 + ... + 2626568.

It is an arithmetic number, because the mean of its divisors is an integer number (59060882700).

Almost surely, 2^918744636221 is an apocalyptic number.

It is an amenable number.

918744636221 is a deficient number, since it is larger than the sum of its proper divisors (26229486979).

918744636221 is a wasteful number, since it uses less digits than its factorization.

918744636221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377308.

The product of its digits is 3483648, while the sum is 53.

The spelling of 918744636221 in words is "nine hundred eighteen billion, seven hundred forty-four million, six hundred thirty-six thousand, two hundred twenty-one".