21632651 has 2 divisors, whose sum is σ = 21632652. Its totient is φ = 21632650.

The previous prime is 21632647. The next prime is 21632657. The reversal of 21632651 is 15623612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21632651 - 2² = 21632647 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21632651.

It is not a weakly prime, because it can be changed into another prime (21632657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10816325 + 10816326.

It is an arithmetic number, because the mean of its divisors is an integer number (10816326).

Almost surely, 2^21632651 is an apocalyptic number.

21632651 is a deficient number, since it is larger than the sum of its proper divisors (1).

21632651 is an equidigital number, since it uses as much as digits as its factorization.

21632651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 26.

The square root of 21632651 is about 4651.0913773006. The cubic root of 21632651 is about 278.6355857740.

The spelling of 21632651 in words is "twenty-one million, six hundred thirty-two thousand, six hundred fifty-one".