21274105 has 4 divisors (see below), whose sum is σ = 25528932. Its totient is φ = 17019280.

The previous prime is 21274093. The next prime is 21274109. The reversal of 21274105 is 50147212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3024121 + 18249984 = 1739^2 + 4272^2 .

It is not a de Polignac number, because 21274105 - 2⁵ = 21274073 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21274109) 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, 2127406 + ... + 2127415.

It is an arithmetic number, because the mean of its divisors is an integer number (6382233).

Almost surely, 2^21274105 is an apocalyptic number.

It is an amenable number.

21274105 is a deficient number, since it is larger than the sum of its proper divisors (4254827).

21274105 is an equidigital number, since it uses as much as digits as its factorization.

21274105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4254826.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21274105 is about 4612.3860419527. The cubic root of 21274105 is about 277.0876053889.

The spelling of 21274105 in words is "twenty-one million, two hundred seventy-four thousand, one hundred five".