21247749230400 has 672 divisors, whose sum is σ = 96568429224960. Its totient is φ = 4415116032000.

The previous prime is 21247749230399. The next prime is 21247749230453. The reversal of 21247749230400 is 403294774212.

21247749230400 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 7 + 7 + 4 + 9 + 230 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 132595 + ... + 6520205.

It is an arithmetic number, because the mean of its divisors is an integer number (143703019680).

Almost surely, 2^{21247749230400} is an apocalyptic number.

21247749230400 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 21247749230400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48284214612480).

21247749230400 is an abundant number, since it is smaller than the sum of its proper divisors (75320679994560).

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

21247749230400 is a wasteful number, since it uses less digits than its factorization.

21247749230400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6387660 (or 6387639 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 45.

The spelling of 21247749230400 in words is "twenty-one trillion, two hundred forty-seven billion, seven hundred forty-nine million, two hundred thirty thousand, four hundred".