21321310 has 32 divisors (see below), whose sum is σ = 39346560. Its totient is φ = 8316672.

The previous prime is 21321301. The next prime is 21321331. The reversal of 21321310 is 1312312.

It is a super-2 number, since 2×21321310² = 909196520232200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108132 + ... + 108328.

It is an arithmetic number, because the mean of its divisors is an integer number (1229580).

Almost surely, 2^21321310 is an apocalyptic number.

21321310 is a deficient number, since it is larger than the sum of its proper divisors (18025250).

21321310 is a wasteful number, since it uses less digits than its factorization.

21321310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420.

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

The square root of 21321310 is about 4617.5004060639. The cubic root of 21321310 is about 277.2923967381.

Adding to 21321310 its reverse (1312312), we get a palindrome (22633622).

The spelling of 21321310 in words is "twenty-one million, three hundred twenty-one thousand, three hundred ten".