21001893472256 has 48 divisors (see below), whose sum is σ = 44463739958820. Its totient is φ = 9883243970560.

The previous prime is 21001893472247. The next prime is 21001893472331. The reversal of 21001893472256 is 65227439810012.

It can be written as a sum of positive squares in 2 ways, for example, as 20952956953600 + 48936518656 = 4577440^2 + 221216^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301577855 + ... + 301647486.

It is a 2-persistent number, because it is pandigital, and so is 2⋅21001893472256 = 42003786944512, but 3⋅21001893472256 = 63005680416768 is not.

Almost surely, 2^{21001893472256} is an apocalyptic number.

It is an amenable number.

21001893472256 is an abundant number, since it is smaller than the sum of its proper divisors (23461846486564).

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

21001893472256 is an equidigital number, since it uses as much as digits as its factorization.

21001893472256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603225380 (or 603225360 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 50.

The spelling of 21001893472256 in words is "twenty-one trillion, one billion, eight hundred ninety-three million, four hundred seventy-two thousand, two hundred fifty-six".