21125829744 has 240 divisors, whose sum is σ = 63477916320. Its totient is φ = 6557469696.

The previous prime is 21125829737. The next prime is 21125829821. The reversal of 21125829744 is 44792852112.

21125829744 is a `hidden beast` number, since 21 + 1 + 2 + 582 + 9 + 7 + 44 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21125829744.

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, 72101662 + ... + 72101954.

It is an arithmetic number, because the mean of its divisors is an integer number (264491318).

Almost surely, 2^21125829744 is an apocalyptic number.

21125829744 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 21125829744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31738958160).

21125829744 is an abundant number, since it is smaller than the sum of its proper divisors (42352086576).

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

21125829744 is a wasteful number, since it uses less digits than its factorization.

21125829744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437 (or 390 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The spelling of 21125829744 in words is "twenty-one billion, one hundred twenty-five million, eight hundred twenty-nine thousand, seven hundred forty-four".