21096049 has 4 divisors (see below), whose sum is σ = 22718836. Its totient is φ = 19473264.

The previous prime is 21096041. The next prime is 21096071. The reversal of 21096049 is 94069012.

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 3186225 + 17909824 = 1785^2 + 4232^2 .

It is a cyclic number.

It is not a de Polignac number, because 21096049 - 2³ = 21096041 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21096049.

It is not an unprimeable number, because it can be changed into a prime (21096041) 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, 811374 + ... + 811399.

It is an arithmetic number, because the mean of its divisors is an integer number (5679709).

Almost surely, 2^21096049 is an apocalyptic number.

It is an amenable number.

21096049 is a deficient number, since it is larger than the sum of its proper divisors (1622787).

21096049 is a wasteful number, since it uses less digits than its factorization.

21096049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622786.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 21096049 is about 4593.0435443179. The cubic root of 21096049 is about 276.3124000641.

The spelling of 21096049 in words is "twenty-one million, ninety-six thousand, forty-nine".