21937529 has 2 divisors, whose sum is σ = 21937530. Its totient is φ = 21937528.

The previous prime is 21937519. The next prime is 21937541. The reversal of 21937529 is 92573912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20839225 + 1098304 = 4565^2 + 1048^2 .

It is a cyclic number.

It is not a de Polignac number, because 21937529 - 2²⁰ = 20888953 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21937492 and 21937501.

It is not a weakly prime, because it can be changed into another prime (21937519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10968764 + 10968765.

It is an arithmetic number, because the mean of its divisors is an integer number (10968765).

Almost surely, 2^21937529 is an apocalyptic number.

It is an amenable number.

21937529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21937529 is an equidigital number, since it uses as much as digits as its factorization.

21937529 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34020, while the sum is 38.

The square root of 21937529 is about 4683.7515946087. The cubic root of 21937529 is about 279.9384601149.

The spelling of 21937529 in words is "twenty-one million, nine hundred thirty-seven thousand, five hundred twenty-nine".