21612012 has 24 divisors (see below), whose sum is σ = 50598912. Its totient is φ = 7179600.

The previous prime is 21612011. The next prime is 21612013. The reversal of 21612012 is 21021612.

It is an interprime number because it is at equal distance from previous prime (21612011) and next prime (21612013).

It is a junction number, because it is equal to n+sod(n) for n = 21611982 and 21612000.

It is not an unprimeable number, because it can be changed into a prime (21612011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 837 + ... + 6627.

It is an arithmetic number, because the mean of its divisors is an integer number (2108288).

Almost surely, 2^21612012 is an apocalyptic number.

It is an amenable number.

21612012 is an abundant number, since it is smaller than the sum of its proper divisors (28986900).

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

21612012 is a wasteful number, since it uses less digits than its factorization.

21612012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6109 (or 6107 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 21612012 is about 4648.8721212785. The cubic root of 21612012 is about 278.5469452325.

Adding to 21612012 its reverse (21021612), we get a palindrome (42633624).

The spelling of 21612012 in words is "twenty-one million, six hundred twelve thousand, twelve".