21751344 has 30 divisors (see below), whose sum is σ = 60873956. Its totient is φ = 7250400.

The previous prime is 21751343. The next prime is 21751351. The reversal of 21751344 is 44315712.

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

It is not an unprimeable number, because it can be changed into a prime (21751343) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 75382 + ... + 75669.

Almost surely, 2^21751344 is an apocalyptic number.

21751344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21751344 is an abundant number, since it is smaller than the sum of its proper divisors (39122612).

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

21751344 is a wasteful number, since it uses less digits than its factorization.

21751344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151065 (or 151056 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21751344 is about 4663.8336162432. The cubic root of 21751344 is about 279.1442580761.

The spelling of 21751344 in words is "twenty-one million, seven hundred fifty-one thousand, three hundred forty-four".