21632797 has 2 divisors, whose sum is σ = 21632798. Its totient is φ = 21632796.

The previous prime is 21632771. The next prime is 21632801. The reversal of 21632797 is 79723612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11431161 + 10201636 = 3381^2 + 3194^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21632797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21632717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10816398 + 10816399.

It is an arithmetic number, because the mean of its divisors is an integer number (10816399).

Almost surely, 2^21632797 is an apocalyptic number.

It is an amenable number.

21632797 is a deficient number, since it is larger than the sum of its proper divisors (1).

21632797 is an equidigital number, since it uses as much as digits as its factorization.

21632797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31752, while the sum is 37.

The square root of 21632797 is about 4651.1070725151. The cubic root of 21632797 is about 278.6362126151.

The spelling of 21632797 in words is "twenty-one million, six hundred thirty-two thousand, seven hundred ninety-seven".