21653955400 has 96 divisors (see below), whose sum is σ = 62768393280. Its totient is φ = 6749280000.

The previous prime is 21653955361. The next prime is 21653955403. The reversal of 21653955400 is 455935612.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (21653955403) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 687651 + ... + 718450.

It is an arithmetic number, because the mean of its divisors is an integer number (653837430).

Almost surely, 2^21653955400 is an apocalyptic number.

21653955400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21653955400 is an abundant number, since it is smaller than the sum of its proper divisors (41114437880).

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

21653955400 is a wasteful number, since it uses less digits than its factorization.

21653955400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1406135 (or 1406126 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 40.

The spelling of 21653955400 in words is "twenty-one billion, six hundred fifty-three million, nine hundred fifty-five thousand, four hundred".