21173266 has 8 divisors (see below), whose sum is σ = 31791420. Its totient is φ = 10576128.

The previous prime is 21173263. The next prime is 21173291. The reversal of 21173266 is 66237112.

It can be written as a sum of positive squares in 2 ways, for example, as 16851025 + 4322241 = 4105^2 + 2079^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21173263) 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, 2431 + ... + 6946.

Almost surely, 2^21173266 is an apocalyptic number.

21173266 is a deficient number, since it is larger than the sum of its proper divisors (10618154).

21173266 is a wasteful number, since it uses less digits than its factorization.

21173266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10508.

The product of its digits is 3024, while the sum is 28.

The square root of 21173266 is about 4601.4417305884. The cubic root of 21173266 is about 276.6491145459.

The spelling of 21173266 in words is "twenty-one million, one hundred seventy-three thousand, two hundred sixty-six".