21402010024400 has 60 divisors (see below), whose sum is σ = 51873358654092. Its totient is φ = 8485044664320.

The previous prime is 21402010024399. The next prime is 21402010024469. The reversal of 21402010024400 is 442001020412.

It can be written as a sum of positive squares in 6 ways, for example, as 7443686369344 + 13958323655056 = 2728312^2 + 3736084^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 236702699 + ... + 236793098.

Almost surely, 2^{21402010024400} is an apocalyptic number.

21402010024400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21402010024400 is an abundant number, since it is smaller than the sum of its proper divisors (30471348629692).

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

21402010024400 is a wasteful number, since it uses less digits than its factorization.

21402010024400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473495928 (or 473495917 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21402010024400 its reverse (442001020412), we get a palindrome (21844011044812).

The spelling of 21402010024400 in words is "twenty-one trillion, four hundred two billion, ten million, twenty-four thousand, four hundred".