21917421351504 has 900 divisors, whose sum is σ = 77185852726752. Its totient is φ = 5985719389440.

The previous prime is 21917421351487. The next prime is 21917421351521. The reversal of 21917421351504 is 40515312471912.

21917421351504 is a `hidden beast` number, since 2 + 1 + 9 + 1 + 7 + 4 + 2 + 135 + 1 + 504 = 666.

It is an interprime number because it is at equal distance from previous prime (21917421351487) and next prime (21917421351521).

It is a self number, because there is not a number n which added to its sum of digits gives 21917421351504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 5065267389 + ... + 5065271715.

Almost surely, 2^{21917421351504} is an apocalyptic number.

21917421351504 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 21917421351504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38592926363376).

21917421351504 is an abundant number, since it is smaller than the sum of its proper divisors (55268431375248).

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

21917421351504 is a wasteful number, since it uses less digits than its factorization.

21917421351504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4506 (or 4453 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The spelling of 21917421351504 in words is "twenty-one trillion, nine hundred seventeen billion, four hundred twenty-one million, three hundred fifty-one thousand, five hundred four".