21372266 has 8 divisors (see below), whose sum is σ = 32161764. Its totient is φ = 10651680.

The previous prime is 21372233. The next prime is 21372269. The reversal of 21372266 is 66227312.

It can be written as a sum of positive squares in 2 ways, for example, as 18879025 + 2493241 = 4345^2 + 1579^2 .

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 (21372269) 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, 16445 + ... + 17696.

Almost surely, 2^21372266 is an apocalyptic number.

21372266 is a deficient number, since it is larger than the sum of its proper divisors (10789498).

21372266 is a wasteful number, since it uses less digits than its factorization.

21372266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34456.

The product of its digits is 6048, while the sum is 29.

The square root of 21372266 is about 4623.0148171945. The cubic root of 21372266 is about 277.5131222321.

Adding to 21372266 its reverse (66227312), we get a palindrome (87599578).

The spelling of 21372266 in words is "twenty-one million, three hundred seventy-two thousand, two hundred sixty-six".