21230690 has 32 divisors (see below), whose sum is σ = 41413680. Its totient is φ = 7789824.

The previous prime is 21230689. The next prime is 21230707. The reversal of 21230690 is 9603212.

It can be written as a sum of positive squares in 8 ways, for example, as 12581209 + 8649481 = 3547^2 + 2941^2 .

It is a super-2 number, since 2×21230690² = 901484395752200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25196 + ... + 26024.

Almost surely, 2^21230690 is an apocalyptic number.

21230690 is a deficient number, since it is larger than the sum of its proper divisors (20182990).

21230690 is a wasteful number, since it uses less digits than its factorization.

21230690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1046.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21230690 is about 4607.6772890471. The cubic root of 21230690 is about 276.8989887444.

The spelling of 21230690 in words is "twenty-one million, two hundred thirty thousand, six hundred ninety".