21009196 has 24 divisors (see below), whose sum is σ = 40874624. Its totient is φ = 9383040.

The previous prime is 21009173. The next prime is 21009199. The reversal of 21009196 is 69190012.

It is not an unprimeable number, because it can be changed into a prime (21009199) 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, 4905 + ... + 8128.

Almost surely, 2^21009196 is an apocalyptic number.

21009196 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21009196 is a deficient number, since it is larger than the sum of its proper divisors (19865428).

21009196 is a wasteful number, since it uses less digits than its factorization.

21009196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13081 (or 13079 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 21009196 is about 4583.5789509945. The cubic root of 21009196 is about 275.9326832957.

The spelling of 21009196 in words is "twenty-one million, nine thousand, one hundred ninety-six".