21795637 has 2 divisors, whose sum is σ = 21795638. Its totient is φ = 21795636.

The previous prime is 21795629. The next prime is 21795643. The reversal of 21795637 is 73659712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19704721 + 2090916 = 4439^2 + 1446^2 .

It is a cyclic number.

It is not a de Polignac number, because 21795637 - 2³ = 21795629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21795637.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21795607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10897818 + 10897819.

It is an arithmetic number, because the mean of its divisors is an integer number (10897819).

Almost surely, 2^21795637 is an apocalyptic number.

It is an amenable number.

21795637 is a deficient number, since it is larger than the sum of its proper divisors (1).

21795637 is an equidigital number, since it uses as much as digits as its factorization.

21795637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 79380, while the sum is 40.

The square root of 21795637 is about 4668.5797626259. The cubic root of 21795637 is about 279.3336065841. Note that the first 3 decimals are identical.

The spelling of 21795637 in words is "twenty-one million, seven hundred ninety-five thousand, six hundred thirty-seven".