21025944 has 24 divisors (see below), whose sum is σ = 56945460. Its totient is φ = 7008624.

The previous prime is 21025937. The next prime is 21025981. The reversal of 21025944 is 44952012.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×21025944² = 884180642182272, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 145942 + ... + 146085.

Almost surely, 2^21025944 is an apocalyptic number.

21025944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21025944 is an abundant number, since it is smaller than the sum of its proper divisors (35919516).

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

21025944 is a wasteful number, since it uses less digits than its factorization.

21025944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292039 (or 292032 counting only the distinct ones).

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

The square root of 21025944 is about 4585.4055436788. The cubic root of 21025944 is about 276.0059860075.

Adding to 21025944 its reverse (44952012), we get a palindrome (65977956).

The spelling of 21025944 in words is "twenty-one million, twenty-five thousand, nine hundred forty-four".