21224130637 has 2 divisors, whose sum is σ = 21224130638. Its totient is φ = 21224130636.

The previous prime is 21224130589. The next prime is 21224130727. The reversal of 21224130637 is 73603142212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20810659081 + 413471556 = 144259^2 + 20334^2 .

It is a cyclic number.

It is not a de Polignac number, because 21224130637 - 2²³ = 21215742029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21224130599 and 21224130608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21224130337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612065318 + 10612065319.

It is an arithmetic number, because the mean of its divisors is an integer number (10612065319).

Almost surely, 2^21224130637 is an apocalyptic number.

It is an amenable number.

21224130637 is a deficient number, since it is larger than the sum of its proper divisors (1).

21224130637 is an equidigital number, since it uses as much as digits as its factorization.

21224130637 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 31.

Adding to 21224130637 its reverse (73603142212), we get a palindrome (94827272849).

The spelling of 21224130637 in words is "twenty-one billion, two hundred twenty-four million, one hundred thirty thousand, six hundred thirty-seven".