21152266 has 4 divisors (see below), whose sum is σ = 31728402. Its totient is φ = 10576132.

The previous prime is 21152239. The next prime is 21152291. The reversal of 21152266 is 66225112.

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., 11758041 + 9394225 = 3429^2 + 3065^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21152266.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5288065 + ... + 5288068.

Almost surely, 2^21152266 is an apocalyptic number.

21152266 is a deficient number, since it is larger than the sum of its proper divisors (10576136).

21152266 is a wasteful number, since it uses less digits than its factorization.

21152266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10576135.

The product of its digits is 1440, while the sum is 25.

The square root of 21152266 is about 4599.1592709973. The cubic root of 21152266 is about 276.5576225490.

Adding to 21152266 its reverse (66225112), we get a palindrome (87377378).

The spelling of 21152266 in words is "twenty-one million, one hundred fifty-two thousand, two hundred sixty-six".