21312707 has 8 divisors (see below), whose sum is σ = 23091936. Its totient is φ = 19553472.

The previous prime is 21312677. The next prime is 21312721. The reversal of 21312707 is 70721312.

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

It is a cyclic number.

It is not a de Polignac number, because 21312707 - 2¹⁰ = 21311683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21312727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2738 + ... + 7079.

It is an arithmetic number, because the mean of its divisors is an integer number (2886492).

Almost surely, 2^21312707 is an apocalyptic number.

21312707 is a deficient number, since it is larger than the sum of its proper divisors (1779229).

21312707 is a wasteful number, since it uses less digits than its factorization.

21312707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9997.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 21312707 is about 4616.5687474574. The cubic root of 21312707 is about 277.2550965376.

The spelling of 21312707 in words is "twenty-one million, three hundred twelve thousand, seven hundred seven".