20664505400 has 144 divisors (see below), whose sum is σ = 60970193640. Its totient is φ = 6440851200.

The previous prime is 20664505373. The next prime is 20664505523. The reversal of 20664505400 is 450546602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 11954 + ... + 203646.

Almost surely, 2^20664505400 is an apocalyptic number.

20664505400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20664505400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30485096820).

20664505400 is an abundant number, since it is smaller than the sum of its proper divisors (40305688240).

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

20664505400 is a wasteful number, since it uses less digits than its factorization.

20664505400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191734 (or 191718 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

The spelling of 20664505400 in words is "twenty billion, six hundred sixty-four million, five hundred five thousand, four hundred".