21210260 has 12 divisors (see below), whose sum is σ = 44541588. Its totient is φ = 8484096.

The previous prime is 21210227. The next prime is 21210269. The reversal of 21210260 is 6201212.

It can be written as a sum of positive squares in 2 ways, for example, as 3334276 + 17875984 = 1826^2 + 4228^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530237 + ... + 530276.

It is an arithmetic number, because the mean of its divisors is an integer number (3711799).

Almost surely, 2^21210260 is an apocalyptic number.

21210260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210260 is an abundant number, since it is smaller than the sum of its proper divisors (23331328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21210260 is a wasteful number, since it uses less digits than its factorization.

21210260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060522 (or 1060520 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21210260 is about 4605.4598033204. The cubic root of 21210260 is about 276.8101415476.

Adding to 21210260 its reverse (6201212), we get a palindrome (27411472).

The spelling of 21210260 in words is "twenty-one million, two hundred ten thousand, two hundred sixty".