21260465 has 4 divisors (see below), whose sum is σ = 25512564. Its totient is φ = 17008368.

The previous prime is 21260443. The next prime is 21260483. The reversal of 21260465 is 56406212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9591409 + 11669056 = 3097^2 + 3416^2 .

It is a cyclic number.

It is not a de Polignac number, because 21260465 - 2⁸ = 21260209 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2126042 + ... + 2126051.

It is an arithmetic number, because the mean of its divisors is an integer number (6378141).

Almost surely, 2^21260465 is an apocalyptic number.

It is an amenable number.

21260465 is a deficient number, since it is larger than the sum of its proper divisors (4252099).

21260465 is an equidigital number, since it uses as much as digits as its factorization.

21260465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4252098.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 21260465 is about 4610.9071775519. The cubic root of 21260465 is about 277.0283740218.

Adding to 21260465 its reverse (56406212), we get a palindrome (77666677).

The spelling of 21260465 in words is "twenty-one million, two hundred sixty thousand, four hundred sixty-five".