21309196 has 12 divisors (see below), whose sum is σ = 37340352. Its totient is φ = 10640528.

The previous prime is 21309193. The next prime is 21309221. The reversal of 21309196 is 69190312.

It is not an unprimeable number, because it can be changed into a prime (21309193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 366 + ... + 6538.

It is an arithmetic number, because the mean of its divisors is an integer number (3111696).

Almost surely, 2^21309196 is an apocalyptic number.

It is an amenable number.

21309196 is a deficient number, since it is larger than the sum of its proper divisors (16031156).

21309196 is a wasteful number, since it uses less digits than its factorization.

21309196 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7040 (or 7038 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 21309196 is about 4616.1884710224. The cubic root of 21309196 is about 277.2398709400.

The spelling of 21309196 in words is "twenty-one million, three hundred nine thousand, one hundred ninety-six".