21490611 has 4 divisors (see below), whose sum is σ = 28654152. Its totient is φ = 14327072.

The previous prime is 21490603. The next prime is 21490613. The reversal of 21490611 is 11609412.

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

It is a cyclic number.

It is not a de Polignac number, because 21490611 - 2³ = 21490603 is a prime.

It is a super-2 number, since 2×21490611² = 923692722306642, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21490613) 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, 3581766 + ... + 3581771.

It is an arithmetic number, because the mean of its divisors is an integer number (7163538).

Almost surely, 2^21490611 is an apocalyptic number.

21490611 is a deficient number, since it is larger than the sum of its proper divisors (7163541).

21490611 is an equidigital number, since it uses as much as digits as its factorization.

21490611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7163540.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 21490611 is about 4635.7966952833. The cubic root of 21490611 is about 278.0244056692.

The spelling of 21490611 in words is "twenty-one million, four hundred ninety thousand, six hundred eleven".