21164433 has 4 divisors (see below), whose sum is σ = 28219248. Its totient is φ = 14109620.

The previous prime is 21164431. The next prime is 21164441. The reversal of 21164433 is 33446112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21164433 - 2¹ = 21164431 is a prime.

It is a super-2 number, since 2×21164433² = 895866448422978, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21164431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3527403 + ... + 3527408.

It is an arithmetic number, because the mean of its divisors is an integer number (7054812).

Almost surely, 2^21164433 is an apocalyptic number.

It is an amenable number.

21164433 is a deficient number, since it is larger than the sum of its proper divisors (7054815).

21164433 is an equidigital number, since it uses as much as digits as its factorization.

21164433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7054814.

The product of its digits is 1728, while the sum is 24.

The square root of 21164433 is about 4600.4818225921. The cubic root of 21164433 is about 276.6106386440.

The spelling of 21164433 in words is "twenty-one million, one hundred sixty-four thousand, four hundred thirty-three".