21152164 has 12 divisors (see below), whose sum is σ = 40381488. Its totient is φ = 9614600.

The previous prime is 21152143. The next prime is 21152207. The reversal of 21152164 is 46125112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240322 + ... + 240409.

It is an arithmetic number, because the mean of its divisors is an integer number (3365124).

Almost surely, 2^21152164 is an apocalyptic number.

It is an amenable number.

21152164 is a deficient number, since it is larger than the sum of its proper divisors (19229324).

21152164 is a wasteful number, since it uses less digits than its factorization.

21152164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480746 (or 480744 counting only the distinct ones).

The product of its digits is 480, while the sum is 22.

The square root of 21152164 is about 4599.1481820007. The cubic root of 21152164 is about 276.5571780116.

Adding to 21152164 its reverse (46125112), we get a palindrome (67277276).

It can be divided in two parts, 21152 and 164, that added together give a square (21316 = 146²).

The spelling of 21152164 in words is "twenty-one million, one hundred fifty-two thousand, one hundred sixty-four".