21298573 has 2 divisors, whose sum is σ = 21298574. Its totient is φ = 21298572.

The previous prime is 21298561. The next prime is 21298583. The reversal of 21298573 is 37589212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17960644 + 3337929 = 4238^2 + 1827^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21298573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21298583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10649286 + 10649287.

It is an arithmetic number, because the mean of its divisors is an integer number (10649287).

Almost surely, 2^21298573 is an apocalyptic number.

It is an amenable number.

21298573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21298573 is an equidigital number, since it uses as much as digits as its factorization.

21298573 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 37.

The square root of 21298573 is about 4615.0377029879. The cubic root of 21298573 is about 277.1937936708.

The spelling of 21298573 in words is "twenty-one million, two hundred ninety-eight thousand, five hundred seventy-three".