21201497 has 2 divisors, whose sum is σ = 21201498. Its totient is φ = 21201496.

The previous prime is 21201487. The next prime is 21201503. The reversal of 21201497 is 79410212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20967241 + 234256 = 4579^2 + 484^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201497 - 2¹⁴ = 21185113 is a prime.

It is not a weakly prime, because it can be changed into another prime (21201487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600748 + 10600749.

It is an arithmetic number, because the mean of its divisors is an integer number (10600749).

Almost surely, 2^21201497 is an apocalyptic number.

It is an amenable number.

21201497 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201497 is an equidigital number, since it uses as much as digits as its factorization.

21201497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 21201497 is about 4604.5083342307. The cubic root of 21201497 is about 276.7720150088.

The spelling of 21201497 in words is "twenty-one million, two hundred one thousand, four hundred ninety-seven".