21255460 has 24 divisors (see below), whose sum is σ = 46077696. Its totient is φ = 8227680.

The previous prime is 21255449. The next prime is 21255467. The reversal of 21255460 is 6455212.

It is not an unprimeable number, because it can be changed into a prime (21255467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16522 + ... + 17761.

It is an arithmetic number, because the mean of its divisors is an integer number (1919904).

Almost surely, 2^21255460 is an apocalyptic number.

21255460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21255460 is an abundant number, since it is smaller than the sum of its proper divisors (24822236).

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

21255460 is a wasteful number, since it uses less digits than its factorization.

21255460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34323 (or 34321 counting only the distinct ones).

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

The square root of 21255460 is about 4610.3644107597. The cubic root of 21255460 is about 277.0066335781.

The spelling of 21255460 in words is "twenty-one million, two hundred fifty-five thousand, four hundred sixty".