21123252768016 has 225 divisors, whose sum is σ = 48382038090743. Its totient is φ = 8933528735040.

The previous prime is 21123252768001. The next prime is 21123252768067. The reversal of 21123252768016 is 61086725232112.

The square root of 21123252768016 is 4596004.

It is a perfect power (a square), and thus also a powerful number.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 118006998615 + ... + 118006998793.

Almost surely, 2^{21123252768016} is an apocalyptic number.

21123252768016 is the 4596004-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123252768016

21123252768016 is an abundant number, since it is smaller than the sum of its proper divisors (27258785322727).

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

21123252768016 is an frugal number, since it uses more digits than its factorization.

21123252768016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 319 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 21123252768016 in words is "twenty-one trillion, one hundred twenty-three billion, two hundred fifty-two million, seven hundred sixty-eight thousand, sixteen".