21340310 has 16 divisors (see below), whose sum is σ = 38577600. Its totient is φ = 8499456.

The previous prime is 21340289. The next prime is 21340313. The reversal of 21340310 is 1304312.

It is a super-2 number, since 2×21340310² = 910817661792200, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21340313) 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, 2075 + ... + 6854.

It is an arithmetic number, because the mean of its divisors is an integer number (2411100).

Almost surely, 2^21340310 is an apocalyptic number.

21340310 is a deficient number, since it is larger than the sum of its proper divisors (17237290).

21340310 is a wasteful number, since it uses less digits than its factorization.

21340310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9175.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21340310 is about 4619.5573381007. The cubic root of 21340310 is about 277.3747398857.

Adding to 21340310 its reverse (1304312), we get a palindrome (22644622).

The spelling of 21340310 in words is "twenty-one million, three hundred forty thousand, three hundred ten".