21970297 has 2 divisors, whose sum is σ = 21970298. Its totient is φ = 21970296.

The previous prime is 21970271. The next prime is 21970303. The reversal of 21970297 is 79207912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17147881 + 4822416 = 4141^2 + 2196^2 .

It is a cyclic number.

It is not a de Polignac number, because 21970297 - 2¹⁵ = 21937529 is a prime.

It is a plaindrome in base 11.

It is not a weakly prime, because it can be changed into another prime (21970097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10985148 + 10985149.

It is an arithmetic number, because the mean of its divisors is an integer number (10985149).

Almost surely, 2^21970297 is an apocalyptic number.

It is an amenable number.

21970297 is a deficient number, since it is larger than the sum of its proper divisors (1).

21970297 is an equidigital number, since it uses as much as digits as its factorization.

21970297 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 21970297 is about 4687.2483399112. The cubic root of 21970297 is about 280.0777717637.

The spelling of 21970297 in words is "twenty-one million, nine hundred seventy thousand, two hundred ninety-seven".