21465013 has 2 divisors, whose sum is σ = 21465014. Its totient is φ = 21465012.

The previous prime is 21464987. The next prime is 21465029. The reversal of 21465013 is 31056412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21464689 + 324 = 4633^2 + 18^2 .

It is a cyclic number.

It is not a de Polignac number, because 21465013 - 2⁹ = 21464501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21465313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10732506 + 10732507.

It is an arithmetic number, because the mean of its divisors is an integer number (10732507).

Almost surely, 2^21465013 is an apocalyptic number.

It is an amenable number.

21465013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21465013 is an equidigital number, since it uses as much as digits as its factorization.

21465013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21465013 is about 4633.0349664124. The cubic root of 21465013 is about 277.9139745558.

The spelling of 21465013 in words is "twenty-one million, four hundred sixty-five thousand, thirteen".