21251248324992 has 480 divisors, whose sum is σ = 73601061827040. Its totient is φ = 6069124454400.

The previous prime is 21251248324987. The next prime is 21251248325137. The reversal of 21251248324992 is 29942384215212.

21251248324992 is a `hidden beast` number, since 2 + 1 + 2 + 51 + 2 + 483 + 24 + 9 + 92 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1356945642 + ... + 1356961302.

It is an arithmetic number, because the mean of its divisors is an integer number (153335545473).

Almost surely, 2^{21251248324992} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21251248324992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36800530913520).

21251248324992 is an abundant number, since it is smaller than the sum of its proper divisors (52349813502048).

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

21251248324992 is a wasteful number, since it uses less digits than its factorization.

21251248324992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18372 (or 18344 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 54.

The spelling of 21251248324992 in words is "twenty-one trillion, two hundred fifty-one billion, two hundred forty-eight million, three hundred twenty-four thousand, nine hundred ninety-two".