21201373 has 2 divisors, whose sum is σ = 21201374. Its totient is φ = 21201372.

The previous prime is 21201347. The next prime is 21201379. The reversal of 21201373 is 37310212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19695844 + 1505529 = 4438^2 + 1227^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201373 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21201373.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600686 + 10600687.

It is an arithmetic number, because the mean of its divisors is an integer number (10600687).

Almost surely, 2^21201373 is an apocalyptic number.

It is an amenable number.

21201373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201373 is an equidigital number, since it uses as much as digits as its factorization.

21201373 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 21201373 is about 4604.4948691469. The cubic root of 21201373 is about 276.7714754275.

Adding to 21201373 its reverse (37310212), we get a palindrome (58511585).

The spelling of 21201373 in words is "twenty-one million, two hundred one thousand, three hundred seventy-three".