21161310 has 32 divisors (see below), whose sum is σ = 51749280. Its totient is φ = 5536128.

The previous prime is 21161297. The next prime is 21161317. The reversal of 21161310 is 1316112.

It is a super-2 number, since 2×21161310² = 895602081832200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21161310.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5065 + ... + 8244.

It is an arithmetic number, because the mean of its divisors is an integer number (1617165).

Almost surely, 2^21161310 is an apocalyptic number.

21161310 is an abundant number, since it is smaller than the sum of its proper divisors (30587970).

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

21161310 is a wasteful number, since it uses less digits than its factorization.

21161310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13372.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 21161310 is about 4600.1423891006. The cubic root of 21161310 is about 276.5970325229.

Adding to 21161310 its reverse (1316112), we get a palindrome (22477422).

The spelling of 21161310 in words is "twenty-one million, one hundred sixty-one thousand, three hundred ten".