21276413 has 4 divisors (see below), whose sum is σ = 21288060. Its totient is φ = 21264768.

The previous prime is 21276407. The next prime is 21276419. The reversal of 21276413 is 31467212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (21276407) and next prime (21276419).

It can be written as a sum of positive squares in 2 ways, for example, as 1545049 + 19731364 = 1243^2 + 4442^2 .

It is a cyclic number.

It is not a de Polignac number, because 21276413 - 2¹⁶ = 21210877 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21276419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2420 + ... + 6957.

It is an arithmetic number, because the mean of its divisors is an integer number (5322015).

Almost surely, 2^21276413 is an apocalyptic number.

It is an amenable number.

21276413 is a deficient number, since it is larger than the sum of its proper divisors (11647).

21276413 is an equidigital number, since it uses as much as digits as its factorization.

21276413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11646.

The product of its digits is 2016, while the sum is 26.

The square root of 21276413 is about 4612.6362310505. The cubic root of 21276413 is about 277.0976253179.

The spelling of 21276413 in words is "twenty-one million, two hundred seventy-six thousand, four hundred thirteen".