21190669 has 4 divisors (see below), whose sum is σ = 21244444. Its totient is φ = 21136896.

The previous prime is 21190667. The next prime is 21190679. The reversal of 21190669 is 96609112.

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 19053225 + 2137444 = 4365^2 + 1462^2 .

It is a cyclic number.

It is not a de Polignac number, because 21190669 - 2¹ = 21190667 is a prime.

It is a super-2 number, since 2×21190669² = 898088905335122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21190661) 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, 26292 + ... + 27085.

It is an arithmetic number, because the mean of its divisors is an integer number (5311111).

Almost surely, 2^21190669 is an apocalyptic number.

It is an amenable number.

21190669 is a deficient number, since it is larger than the sum of its proper divisors (53775).

21190669 is an equidigital number, since it uses as much as digits as its factorization.

21190669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53774.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 21190669 is about 4603.3323799178. The cubic root of 21190669 is about 276.7248894417.

The spelling of 21190669 in words is "twenty-one million, one hundred ninety thousand, six hundred sixty-nine".