21265895 has 32 divisors (see below), whose sum is σ = 31269888. Its totient is φ = 13552128.

The previous prime is 21265891. The next prime is 21265897. The reversal of 21265895 is 59856212.

It is not a de Polignac number, because 21265895 - 2² = 21265891 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21265891) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 61112 + ... + 61458.

It is an arithmetic number, because the mean of its divisors is an integer number (977184).

Almost surely, 2^21265895 is an apocalyptic number.

21265895 is a deficient number, since it is larger than the sum of its proper divisors (10003993).

21265895 is a wasteful number, since it uses less digits than its factorization.

21265895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 479.

The product of its digits is 43200, while the sum is 38.

The square root of 21265895 is about 4611.4959611822. The cubic root of 21265895 is about 277.0519566986.

The spelling of 21265895 in words is "twenty-one million, two hundred sixty-five thousand, eight hundred ninety-five".