21295997 has 2 divisors, whose sum is σ = 21295998. Its totient is φ = 21295996.

The previous prime is 21295961. The next prime is 21296021. The reversal of 21295997 is 79959212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20894041 + 401956 = 4571^2 + 634^2 .

It is a cyclic number.

It is not a de Polignac number, because 21295997 - 2¹⁴ = 21279613 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21295697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10647998 + 10647999.

It is an arithmetic number, because the mean of its divisors is an integer number (10647999).

Almost surely, 2^21295997 is an apocalyptic number.

It is an amenable number.

21295997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21295997 is an equidigital number, since it uses as much as digits as its factorization.

21295997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 102060, while the sum is 44.

The square root of 21295997 is about 4614.7586069046. The cubic root of 21295997 is about 277.1826179612.

The spelling of 21295997 in words is "twenty-one million, two hundred ninety-five thousand, nine hundred ninety-seven".