21312310 has 8 divisors (see below), whose sum is σ = 38362176. Its totient is φ = 8524920.

The previous prime is 21312299. The next prime is 21312323. The reversal of 21312310 is 1321312.

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

It is a super-2 number, since 2×21312310² = 908429115072200, which contains 22 as substring.

It is a congruent 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, 1065606 + ... + 1065625.

It is an arithmetic number, because the mean of its divisors is an integer number (4795272).

Almost surely, 2^21312310 is an apocalyptic number.

21312310 is a deficient number, since it is larger than the sum of its proper divisors (17049866).

21312310 is a wasteful number, since it uses less digits than its factorization.

21312310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2131238.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21312310 is about 4616.5257499553. The cubic root of 21312310 is about 277.2533750144.

Adding to 21312310 its reverse (1321312), we get a palindrome (22633622).

The spelling of 21312310 in words is "twenty-one million, three hundred twelve thousand, three hundred ten".