21265867 has 8 divisors (see below), whose sum is σ = 24667136. Its totient is φ = 17955432.

The previous prime is 21265859. The next prime is 21265873. The reversal of 21265867 is 76856212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21265867 - 2³ = 21265859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21265817) 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, 22203 + ... + 23140.

It is an arithmetic number, because the mean of its divisors is an integer number (3083392).

Almost surely, 2^21265867 is an apocalyptic number.

21265867 is a deficient number, since it is larger than the sum of its proper divisors (3401269).

21265867 is an equidigital number, since it uses as much as digits as its factorization.

21265867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45417.

The product of its digits is 40320, while the sum is 37.

The square root of 21265867 is about 4611.4929252900. The cubic root of 21265867 is about 277.0518351039.

The spelling of 21265867 in words is "twenty-one million, two hundred sixty-five thousand, eight hundred sixty-seven".