21279495 has 16 divisors (see below), whose sum is σ = 36050400. Its totient is φ = 10681344.

The previous prime is 21279493. The next prime is 21279497. The reversal of 21279495 is 59497212.

It is an interprime number because it is at equal distance from previous prime (21279493) and next prime (21279497).

It is not a de Polignac number, because 21279495 - 2¹ = 21279493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21279493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41470 + ... + 41979.

It is an arithmetic number, because the mean of its divisors is an integer number (2253150).

Almost surely, 2^21279495 is an apocalyptic number.

21279495 is a deficient number, since it is larger than the sum of its proper divisors (14770905).

21279495 is a wasteful number, since it uses less digits than its factorization.

21279495 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83474.

The product of its digits is 45360, while the sum is 39.

The square root of 21279495 is about 4612.9703012267. The cubic root of 21279495 is about 277.1110043533. Note that the first 3 decimals are identical.

The spelling of 21279495 in words is "twenty-one million, two hundred seventy-nine thousand, four hundred ninety-five".