21256270 has 32 divisors (see below), whose sum is σ = 44038656. Its totient is φ = 7236000.

The previous prime is 21256259. The next prime is 21256283. The reversal of 21256270 is 7265212.

It is a Smith number, since the sum of its digits (25) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent 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, 9565 + ... + 11575.

It is an arithmetic number, because the mean of its divisors is an integer number (1376208).

Almost surely, 2^21256270 is an apocalyptic number.

21256270 is an abundant number, since it is smaller than the sum of its proper divisors (22782386).

21256270 is a wasteful number, since it uses less digits than its factorization.

21256270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2176.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21256270 is about 4610.4522554734. The cubic root of 21256270 is about 277.0101522430.

The spelling of 21256270 in words is "twenty-one million, two hundred fifty-six thousand, two hundred seventy".