21260489 has 8 divisors (see below), whose sum is σ = 22644360. Its totient is φ = 19891456.

The previous prime is 21260483. The next prime is 21260501. The reversal of 21260489 is 98406212.

It can be written as a sum of positive squares in 4 ways, for example, as 17707264 + 3553225 = 4208^2 + 1885^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21260489 - 2⁸ = 21260233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21260483) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 674 + ... + 6555.

It is an arithmetic number, because the mean of its divisors is an integer number (2830545).

Almost surely, 2^21260489 is an apocalyptic number.

It is an amenable number.

21260489 is a deficient number, since it is larger than the sum of its proper divisors (1383871).

21260489 is a wasteful number, since it uses less digits than its factorization.

21260489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7419.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 21260489 is about 4610.9097800759. The cubic root of 21260489 is about 277.0284782634.

The spelling of 21260489 in words is "twenty-one million, two hundred sixty thousand, four hundred eighty-nine".