21250944 has 256 divisors, whose sum is σ = 75398400. Its totient is φ = 5806080.

The previous prime is 21250877. The next prime is 21250961. The reversal of 21250944 is 44905212.

It is a super-2 number, since 2×21250944² = 903205241782272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 494187 + ... + 494229.

It is an arithmetic number, because the mean of its divisors is an integer number (294525).

Almost surely, 2^21250944 is an apocalyptic number.

21250944 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 21250944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37699200).

21250944 is an abundant number, since it is smaller than the sum of its proper divisors (54147456).

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

21250944 is a wasteful number, since it uses less digits than its factorization.

21250944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 21250944 is about 4609.8746186854. The cubic root of 21250944 is about 276.9870142965.

The spelling of 21250944 in words is "twenty-one million, two hundred fifty thousand, nine hundred forty-four".