21255045 has 64 divisors (see below), whose sum is σ = 40919040. Its totient is φ = 9220608.

The previous prime is 21255019. The next prime is 21255061. The reversal of 21255045 is 54055212.

It is a happy number.

It is not a de Polignac number, because 21255045 - 2⁸ = 21254789 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 291129 + ... + 291201.

It is an arithmetic number, because the mean of its divisors is an integer number (639360).

Almost surely, 2^21255045 is an apocalyptic number.

It is an amenable number.

21255045 is a deficient number, since it is larger than the sum of its proper divisors (19663995).

21255045 is a wasteful number, since it uses less digits than its factorization.

21255045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194.

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 21255045 is about 4610.3194032518. The cubic root of 21255045 is about 277.0048307707.

The spelling of 21255045 in words is "twenty-one million, two hundred fifty-five thousand, forty-five".