21272999 has 16 divisors (see below), whose sum is σ = 24744960. Its totient is φ = 18094560.

The previous prime is 21272987. The next prime is 21273011. The reversal of 21272999 is 99927212.

It is an interprime number because it is at equal distance from previous prime (21272987) and next prime (21273011).

It is not a de Polignac number, because 21272999 - 2¹² = 21268903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272099) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10997 + ... + 12785.

It is an arithmetic number, because the mean of its divisors is an integer number (1546560).

Almost surely, 2^21272999 is an apocalyptic number.

21272999 is a deficient number, since it is larger than the sum of its proper divisors (3471961).

21272999 is a wasteful number, since it uses less digits than its factorization.

21272999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1870.

The product of its digits is 40824, while the sum is 41.

The square root of 21272999 is about 4612.2661458333. The cubic root of 21272999 is about 277.0828035542.

The spelling of 21272999 in words is "twenty-one million, two hundred seventy-two thousand, nine hundred ninety-nine".