20691056208 has 20 divisors (see below), whose sum is σ = 53451895328. Its totient is φ = 6897018720.

The previous prime is 20691056189. The next prime is 20691056209. The reversal of 20691056208 is 80265019602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20691056209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215531788 + ... + 215531883.

Almost surely, 2^20691056208 is an apocalyptic number.

It is an amenable number.

20691056208 is an abundant number, since it is smaller than the sum of its proper divisors (32760839120).

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

20691056208 is a wasteful number, since it uses less digits than its factorization.

20691056208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431063682 (or 431063676 counting only the distinct ones).

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

The spelling of 20691056208 in words is "twenty billion, six hundred ninety-one million, fifty-six thousand, two hundred eight".