21123254241504 has 288 divisors, whose sum is σ = 61449237577728. Its totient is φ = 6881696640000.

The previous prime is 21123254241491. The next prime is 21123254241511. The reversal of 21123254241504 is 40514245232112.

21123254241504 is a `hidden beast` number, since 2 + 1 + 1 + 23 + 2 + 542 + 41 + 50 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 727796337 + ... + 727825359.

It is an arithmetic number, because the mean of its divisors is an integer number (213365408256).

Almost surely, 2^{21123254241504} is an apocalyptic number.

21123254241504 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 21123254241504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30724618788864).

21123254241504 is an abundant number, since it is smaller than the sum of its proper divisors (40325983336224).

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

21123254241504 is a wasteful number, since it uses less digits than its factorization.

21123254241504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29462 (or 29451 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

Adding to 21123254241504 its reverse (40514245232112), we get a palindrome (61637499473616).

The spelling of 21123254241504 in words is "twenty-one trillion, one hundred twenty-three billion, two hundred fifty-four million, two hundred forty-one thousand, five hundred four".