21353400 has 72 divisors (see below), whose sum is σ = 71717880. Its totient is φ = 5693760.

The previous prime is 21353383. The next prime is 21353401. The reversal of 21353400 is 435312.

21353400 is a `hidden beast` number, since 213 + 53 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21353401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4132 + ... + 7731.

Almost surely, 2^21353400 is an apocalyptic number.

21353400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21353400 is an abundant number, since it is smaller than the sum of its proper divisors (50364480).

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

21353400 is a wasteful number, since it uses less digits than its factorization.

21353400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11885 (or 11873 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21353400 is about 4620.9739233196. The cubic root of 21353400 is about 277.4314415490.

Adding to 21353400 its reverse (435312), we get a palindrome (21788712).

The spelling of 21353400 in words is "twenty-one million, three hundred fifty-three thousand, four hundred".