21274849 has 4 divisors (see below), whose sum is σ = 21463236. Its totient is φ = 21086464.

The previous prime is 21274831. The next prime is 21274861. The reversal of 21274849 is 94847212.

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 10679824 + 10595025 = 3268^2 + 3255^2 .

It is a cyclic number.

It is not a de Polignac number, because 21274849 - 2⁵ = 21274817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21274819) 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, 94024 + ... + 94249.

It is an arithmetic number, because the mean of its divisors is an integer number (5365809).

Almost surely, 2^21274849 is an apocalyptic number.

It is an amenable number.

21274849 is a deficient number, since it is larger than the sum of its proper divisors (188387).

21274849 is a wasteful number, since it uses less digits than its factorization.

21274849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188386.

The product of its digits is 32256, while the sum is 37.

The square root of 21274849 is about 4612.4666936467. The cubic root of 21274849 is about 277.0908354625.

The spelling of 21274849 in words is "twenty-one million, two hundred seventy-four thousand, eight hundred forty-nine".