21321663604 has 12 divisors (see below), whose sum is σ = 37785227200. Its totient is φ = 10525884408.

The previous prime is 21321663593. The next prime is 21321663641. The reversal of 21321663604 is 40636612312.

It is a super-2 number, since 2×21321663604² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21321663604.

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, 33736494 + ... + 33737125.

Almost surely, 2^21321663604 is an apocalyptic number.

It is an amenable number.

21321663604 is a deficient number, since it is larger than the sum of its proper divisors (16463563596).

21321663604 is a wasteful number, since it uses less digits than its factorization.

21321663604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67473702 (or 67473700 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 34.

The spelling of 21321663604 in words is "twenty-one billion, three hundred twenty-one million, six hundred sixty-three thousand, six hundred four".