21650297 has 2 divisors, whose sum is σ = 21650298. Its totient is φ = 21650296.

The previous prime is 21650287. The next prime is 21650339. The reversal of 21650297 is 79205612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21631801 + 18496 = 4651^2 + 136^2 .

It is a cyclic number.

It is not a de Polignac number, because 21650297 - 2⁴ = 21650281 is a prime.

It is not a weakly prime, because it can be changed into another prime (21650257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10825148 + 10825149.

It is an arithmetic number, because the mean of its divisors is an integer number (10825149).

Almost surely, 2^21650297 is an apocalyptic number.

It is an amenable number.

21650297 is a deficient number, since it is larger than the sum of its proper divisors (1).

21650297 is an equidigital number, since it uses as much as digits as its factorization.

21650297 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 21650297 is about 4652.9879647384. The cubic root of 21650297 is about 278.7113272578.

The spelling of 21650297 in words is "twenty-one million, six hundred fifty thousand, two hundred ninety-seven".