20653720400 has 30 divisors (see below), whose sum is σ = 49620564222. Its totient is φ = 8261488000.

The previous prime is 20653720349. The next prime is 20653720411. The reversal of 20653720400 is 402735602.

It can be written as a sum of positive squares in 3 ways, for example, as 2115264064 + 18538456336 = 45992^2 + 136156^2 .

It is a super-2 number, since 2×20653720400² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25816751 + ... + 25817550.

Almost surely, 2^20653720400 is an apocalyptic number.

20653720400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20653720400 is an abundant number, since it is smaller than the sum of its proper divisors (28966843822).

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

20653720400 is a wasteful number, since it uses less digits than its factorization.

20653720400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51634319 (or 51634308 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 29.

The spelling of 20653720400 in words is "twenty billion, six hundred fifty-three million, seven hundred twenty thousand, four hundred".