21256466 has 32 divisors (see below), whose sum is σ = 40255488. Its totient is φ = 8177040.

The previous prime is 21256457. The next prime is 21256471. The reversal of 21256466 is 66465212.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11951 + ... + 13613.

It is an arithmetic number, because the mean of its divisors is an integer number (1257984).

Almost surely, 2^21256466 is an apocalyptic number.

21256466 is a deficient number, since it is larger than the sum of its proper divisors (18999022).

21256466 is a wasteful number, since it uses less digits than its factorization.

21256466 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1766.

The product of its digits is 17280, while the sum is 32.

The square root of 21256466 is about 4610.4735114736. The cubic root of 21256466 is about 277.0110036595.

The spelling of 21256466 in words is "twenty-one million, two hundred fifty-six thousand, four hundred sixty-six".