21312110 has 32 divisors (see below), whose sum is σ = 40642560. Its totient is φ = 8023968.

The previous prime is 21312107. The next prime is 21312113. The reversal of 21312110 is 1121312.

It is an interprime number because it is at equal distance from previous prime (21312107) and next prime (21312113).

It is a junction number, because it is equal to n+sod(n) for n = 21312091 and 21312100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42119 + ... + 42621.

It is an arithmetic number, because the mean of its divisors is an integer number (1270080).

Almost surely, 2^21312110 is an apocalyptic number.

21312110 is a deficient number, since it is larger than the sum of its proper divisors (19330450).

21312110 is a wasteful number, since it uses less digits than its factorization.

21312110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21312110 is about 4616.5040885934. The cubic root of 21312110 is about 277.2525077403.

Adding to 21312110 its reverse (1121312), we get a palindrome (22433422).

The spelling of 21312110 in words is "twenty-one million, three hundred twelve thousand, one hundred ten".