21056254 has 8 divisors (see below), whose sum is σ = 32603328. Its totient is φ = 10188480.

The previous prime is 21056249. The next prime is 21056263. The reversal of 21056254 is 45265012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169747 + ... + 169870.

It is an arithmetic number, because the mean of its divisors is an integer number (4075416).

Almost surely, 2^21056254 is an apocalyptic number.

21056254 is a deficient number, since it is larger than the sum of its proper divisors (11547074).

21056254 is a wasteful number, since it uses less digits than its factorization.

21056254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339650.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 21056254 is about 4588.7094046148. The cubic root of 21056254 is about 276.1385480266.

The spelling of 21056254 in words is "twenty-one million, fifty-six thousand, two hundred fifty-four".