21161232 has 30 divisors (see below), whose sum is σ = 59222462. Its totient is φ = 7053696.

The previous prime is 21161227. The next prime is 21161237. The reversal of 21161232 is 23216112.

21161232 is a `hidden beast` number, since 21 + 1 + 612 + 32 = 666.

It is an interprime number because it is at equal distance from previous prime (21161227) and next prime (21161237).

It can be written as a sum of positive squares in only one way, i.e., 11943936 + 9217296 = 3456^2 + 3036^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is not an unprimeable number, because it can be changed into a prime (21161237) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73333 + ... + 73620.

Almost surely, 2^21161232 is an apocalyptic number.

It is an amenable number.

21161232 is an abundant number, since it is smaller than the sum of its proper divisors (38061230).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21161232 is a wasteful number, since it uses less digits than its factorization.

21161232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146967 (or 146958 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 21161232 is about 4600.1339110943. The cubic root of 21161232 is about 276.5966926794.

Adding to 21161232 its reverse (23216112), we get a palindrome (44377344).

The spelling of 21161232 in words is "twenty-one million, one hundred sixty-one thousand, two hundred thirty-two".