21356969684 has 24 divisors (see below), whose sum is σ = 39350455200. Its totient is φ = 10114230240.

The previous prime is 21356969671. The next prime is 21356969687. The reversal of 21356969684 is 48696965312.

It is a super-2 number, since 2×21356969684² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21356969687) 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, 346262 + ... + 403250.

It is an arithmetic number, because the mean of its divisors is an integer number (1639602300).

Almost surely, 2^21356969684 is an apocalyptic number.

It is an amenable number.

21356969684 is a deficient number, since it is larger than the sum of its proper divisors (17993485516).

21356969684 is a wasteful number, since it uses less digits than its factorization.

21356969684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61943 (or 61941 counting only the distinct ones).

The product of its digits is 16796160, while the sum is 59.

The spelling of 21356969684 in words is "twenty-one billion, three hundred fifty-six million, nine hundred sixty-nine thousand, six hundred eighty-four".