21582266 has 4 divisors (see below), whose sum is σ = 32373402. Its totient is φ = 10791132.

The previous prime is 21582263. The next prime is 21582287. The reversal of 21582266 is 66228512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21576025 + 6241 = 4645^2 + 79^2 .

It is not an unprimeable number, because it can be changed into a prime (21582263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5395565 + ... + 5395568.

Almost surely, 2^21582266 is an apocalyptic number.

21582266 is a deficient number, since it is larger than the sum of its proper divisors (10791136).

21582266 is a wasteful number, since it uses less digits than its factorization.

21582266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10791135.

The product of its digits is 11520, while the sum is 32.

The square root of 21582266 is about 4645.6717490585. The cubic root of 21582266 is about 278.4190925411.

The spelling of 21582266 in words is "twenty-one million, five hundred eighty-two thousand, two hundred sixty-six".