21995015 has 32 divisors (see below), whose sum is σ = 31933440. Its totient is φ = 14217984.

The previous prime is 21994993. The next prime is 21995033. The reversal of 21995015 is 51059912.

It is a cyclic number.

It is not a de Polignac number, because 21995015 - 2⁸ = 21994759 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71492 + ... + 71798.

It is an arithmetic number, because the mean of its divisors is an integer number (997920).

Almost surely, 2^21995015 is an apocalyptic number.

21995015 is a deficient number, since it is larger than the sum of its proper divisors (9938425).

21995015 is a wasteful number, since it uses less digits than its factorization.

21995015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431.

The product of its (nonzero) digits is 4050, while the sum is 32.

The square root of 21995015 is about 4689.8843269317. The cubic root of 21995015 is about 280.1827675788.

The spelling of 21995015 in words is "twenty-one million, nine hundred ninety-five thousand, fifteen".