21312610 has 16 divisors (see below), whose sum is σ = 41850432. Its totient is φ = 7750000.

The previous prime is 21312587. The next prime is 21312619. The reversal of 21312610 is 1621312.

It is not an unprimeable number, because it can be changed into a prime (21312619) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96766 + ... + 96985.

It is an arithmetic number, because the mean of its divisors is an integer number (2615652).

Almost surely, 2^21312610 is an apocalyptic number.

21312610 is a deficient number, since it is larger than the sum of its proper divisors (20537822).

21312610 is a wasteful number, since it uses less digits than its factorization.

21312610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193769.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21312610 is about 4616.5582418074. The cubic root of 21312610 is about 277.2546759155.

Adding to 21312610 its reverse (1621312), we get a palindrome (22933922).

The spelling of 21312610 in words is "twenty-one million, three hundred twelve thousand, six hundred ten".