21295321 has 2 divisors, whose sum is σ = 21295322. Its totient is φ = 21295320.

The previous prime is 21295303. The next prime is 21295349. The reversal of 21295321 is 12359212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14592400 + 6702921 = 3820^2 + 2589^2 .

It is a cyclic number.

It is not a de Polignac number, because 21295321 - 2⁵ = 21295289 is a prime.

It is not a weakly prime, because it can be changed into another prime (21295301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10647660 + 10647661.

It is an arithmetic number, because the mean of its divisors is an integer number (10647661).

Almost surely, 2^21295321 is an apocalyptic number.

It is an amenable number.

21295321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21295321 is an equidigital number, since it uses as much as digits as its factorization.

21295321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 25.

The square root of 21295321 is about 4614.6853630556. The cubic root of 21295321 is about 277.1796850558.

The spelling of 21295321 in words is "twenty-one million, two hundred ninety-five thousand, three hundred twenty-one".