21213663608 has 8 divisors (see below), whose sum is σ = 39775619280. Its totient is φ = 10606831800.

The previous prime is 21213663593. The next prime is 21213663613. The reversal of 21213663608 is 80636631212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1325853968 + ... + 1325853983.

It is an arithmetic number, because the mean of its divisors is an integer number (4971952410).

Almost surely, 2^21213663608 is an apocalyptic number.

It is an amenable number.

21213663608 is a deficient number, since it is larger than the sum of its proper divisors (18561955672).

21213663608 is a wasteful number, since it uses less digits than its factorization.

21213663608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2651707957 (or 2651707953 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 38.

The spelling of 21213663608 in words is "twenty-one billion, two hundred thirteen million, six hundred sixty-three thousand, six hundred eight".