20451656208 has 40 divisors (see below), whose sum is σ = 52838798656. Its totient is φ = 6816528000.

The previous prime is 20451656179. The next prime is 20451656209. The reversal of 20451656208 is 80265615402.

It is not an unprimeable number, because it can be changed into a prime (20451656209) 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, 719058 + ... + 746958.

Almost surely, 2^20451656208 is an apocalyptic number.

It is an amenable number.

20451656208 is an abundant number, since it is smaller than the sum of its proper divisors (32387142448).

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

20451656208 is a wasteful number, since it uses less digits than its factorization.

20451656208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43183 (or 43177 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 39.

The spelling of 20451656208 in words is "twenty billion, four hundred fifty-one million, six hundred fifty-six thousand, two hundred eight".