21662633 has 2 divisors, whose sum is σ = 21662634. Its totient is φ = 21662632.

The previous prime is 21662609. The next prime is 21662653. The reversal of 21662633 is 33626612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11505664 + 10156969 = 3392^2 + 3187^2 .

It is a cyclic number.

It is not a de Polignac number, because 21662633 - 2⁶ = 21662569 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21662596 and 21662605.

It is not a weakly prime, because it can be changed into another prime (21662653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10831316 + 10831317.

It is an arithmetic number, because the mean of its divisors is an integer number (10831317).

Almost surely, 2^21662633 is an apocalyptic number.

It is an amenable number.

21662633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21662633 is an equidigital number, since it uses as much as digits as its factorization.

21662633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 29.

The square root of 21662633 is about 4654.3133757838. The cubic root of 21662633 is about 278.7642523228.

The spelling of 21662633 in words is "twenty-one million, six hundred sixty-two thousand, six hundred thirty-three".