21315310 has 8 divisors (see below), whose sum is σ = 38367576. Its totient is φ = 8526120.

The previous prime is 21315289. The next prime is 21315341. The reversal of 21315310 is 1351312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21315310² = 908684880792200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1065756 + ... + 1065775.

It is an arithmetic number, because the mean of its divisors is an integer number (4795947).

Almost surely, 2^21315310 is an apocalyptic number.

21315310 is a deficient number, since it is larger than the sum of its proper divisors (17052266).

21315310 is a wasteful number, since it uses less digits than its factorization.

21315310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2131538.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 21315310 is about 4616.8506581868. The cubic root of 21315310 is about 277.2663834761.

Adding to 21315310 its reverse (1351312), we get a palindrome (22666622).

The spelling of 21315310 in words is "twenty-one million, three hundred fifteen thousand, three hundred ten".