21500669208 has 16 divisors (see below), whose sum is σ = 53751673080. Its totient is φ = 7166889728.

The previous prime is 21500669191. The next prime is 21500669227. The reversal of 21500669208 is 80296600512.

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, 447930585 + ... + 447930632.

Almost surely, 2^21500669208 is an apocalyptic number.

It is an amenable number.

21500669208 is an abundant number, since it is smaller than the sum of its proper divisors (32251003872).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21500669208 is a wasteful number, since it uses less digits than its factorization.

21500669208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 895861226 (or 895861222 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The spelling of 21500669208 in words is "twenty-one billion, five hundred million, six hundred sixty-nine thousand, two hundred eight".