21365254 has 12 divisors (see below), whose sum is σ = 32672556. Its totient is φ = 10478312.

The previous prime is 21365233. The next prime is 21365269. The reversal of 21365254 is 45256312.

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 5 ways as a sum of consecutive naturals, for example, 3717 + ... + 7519.

It is an arithmetic number, because the mean of its divisors is an integer number (2722713).

Almost surely, 2^21365254 is an apocalyptic number.

21365254 is a deficient number, since it is larger than the sum of its proper divisors (11307302).

21365254 is an equidigital number, since it uses as much as digits as its factorization.

21365254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3911 (or 3858 counting only the distinct ones).

The product of its digits is 7200, while the sum is 28.

The square root of 21365254 is about 4622.2563754080. The cubic root of 21365254 is about 277.4827692680.

The spelling of 21365254 in words is "twenty-one million, three hundred sixty-five thousand, two hundred fifty-four".