21252373 has 2 divisors, whose sum is σ = 21252374. Its totient is φ = 21252372.

The previous prime is 21252367. The next prime is 21252377. The reversal of 21252373 is 37325212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13089924 + 8162449 = 3618^2 + 2857^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21252373 is a prime.

It is a super-2 number, since 2×21252373² = 903326716262258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21252377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10626186 + 10626187.

It is an arithmetic number, because the mean of its divisors is an integer number (10626187).

Almost surely, 2^21252373 is an apocalyptic number.

It is an amenable number.

21252373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21252373 is an equidigital number, since it uses as much as digits as its factorization.

21252373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 25.

The square root of 21252373 is about 4610.0296094494. The cubic root of 21252373 is about 276.9932227356.

Adding to 21252373 its reverse (37325212), we get a palindrome (58577585).

The spelling of 21252373 in words is "twenty-one million, two hundred fifty-two thousand, three hundred seventy-three".