21253413015744 has 448 divisors, whose sum is σ = 73628519150592. Its totient is φ = 5250554265600.

The previous prime is 21253413015707. The next prime is 21253413015763. The reversal of 21253413015744 is 44751031435212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 21253413015696 and 21253413015705.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 62502504 + ... + 62841624.

It is an arithmetic number, because the mean of its divisors is an integer number (164349373104).

Almost surely, 2^{21253413015744} is an apocalyptic number.

21253413015744 is a gapful number since it is divisible by the number (24) 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 21253413015744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36814259575296).

21253413015744 is an abundant number, since it is smaller than the sum of its proper divisors (52375106134848).

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

21253413015744 is a wasteful number, since it uses less digits than its factorization.

21253413015744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339384 (or 339374 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 42.

The spelling of 21253413015744 in words is "twenty-one trillion, two hundred fifty-three billion, four hundred thirteen million, fifteen thousand, seven hundred forty-four".