21312410 has 32 divisors (see below), whose sum is σ = 44053632. Its totient is φ = 7272000.

The previous prime is 21312341. The next prime is 21312427. The reversal of 21312410 is 1421312.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16964 + ... + 18176.

It is an arithmetic number, because the mean of its divisors is an integer number (1376676).

Almost surely, 2^21312410 is an apocalyptic number.

21312410 is an abundant number, since it is smaller than the sum of its proper divisors (22741222).

21312410 is a wasteful number, since it uses less digits than its factorization.

21312410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1478.

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

The square root of 21312410 is about 4616.5365805981. The cubic root of 21312410 is about 277.2538086495.

Adding to 21312410 its reverse (1421312), we get a palindrome (22733722).

The spelling of 21312410 in words is "twenty-one million, three hundred twelve thousand, four hundred ten".