21395461 has 2 divisors, whose sum is σ = 21395462. Its totient is φ = 21395460.

The previous prime is 21395447. The next prime is 21395477. The reversal of 21395461 is 16459312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10956100 + 10439361 = 3310^2 + 3231^2 .

It is a cyclic number.

It is not a de Polignac number, because 21395461 - 2⁹ = 21394949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21395161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10697730 + 10697731.

It is an arithmetic number, because the mean of its divisors is an integer number (10697731).

Almost surely, 2^21395461 is an apocalyptic number.

It is an amenable number.

21395461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21395461 is an equidigital number, since it uses as much as digits as its factorization.

21395461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 31.

The square root of 21395461 is about 4625.5227812648. The cubic root of 21395461 is about 277.6134795463.

The spelling of 21395461 in words is "twenty-one million, three hundred ninety-five thousand, four hundred sixty-one".