21232116 has 36 divisors (see below), whose sum is σ = 56828772. Its totient is φ = 6660864.

The previous prime is 21232103. The next prime is 21232121. The reversal of 21232116 is 61123212.

It can be written as a sum of positive squares in 2 ways, for example, as 15210000 + 6022116 = 3900^2 + 2454^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16735 + ... + 17958.

It is an arithmetic number, because the mean of its divisors is an integer number (1578577).

Almost surely, 2^21232116 is an apocalyptic number.

It is an amenable number.

21232116 is an abundant number, since it is smaller than the sum of its proper divisors (35596656).

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

21232116 is a wasteful number, since it uses less digits than its factorization.

21232116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34720 (or 34715 counting only the distinct ones).

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

The square root of 21232116 is about 4607.8320281885. The cubic root of 21232116 is about 276.9051880894.

Adding to 21232116 its reverse (61123212), we get a palindrome (82355328).

The spelling of 21232116 in words is "twenty-one million, two hundred thirty-two thousand, one hundred sixteen".