21311310 has 16 divisors (see below), whose sum is σ = 51147216. Its totient is φ = 5683008.

The previous prime is 21311261. The next prime is 21311347. The reversal of 21311310 is 1311312.

It is a super-2 number, since 2×21311310² = 908343867832200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 355159 + ... + 355218.

It is an arithmetic number, because the mean of its divisors is an integer number (3196701).

Almost surely, 2^21311310 is an apocalyptic number.

21311310 is an abundant number, since it is smaller than the sum of its proper divisors (29835906).

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

21311310 is a wasteful number, since it uses less digits than its factorization.

21311310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710387.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 21311310 is about 4616.4174421298. The cubic root of 21311310 is about 277.2490385893.

Adding to 21311310 its reverse (1311312), we get a palindrome (22622622).

The spelling of 21311310 in words is "twenty-one million, three hundred eleven thousand, three hundred ten".