21016612 has 6 divisors (see below), whose sum is σ = 36779078. Its totient is φ = 10508304.

The previous prime is 21016609. The next prime is 21016613. The reversal of 21016612 is 21661012.

It can be written as a sum of positive squares in only one way, i.e., 10929636 + 10086976 = 3306^2 + 3176^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21016612.

It is not an unprimeable number, because it can be changed into a prime (21016613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2627073 + ... + 2627080.

Almost surely, 2^21016612 is an apocalyptic number.

It is an amenable number.

21016612 is a deficient number, since it is larger than the sum of its proper divisors (15762466).

21016612 is a wasteful number, since it uses less digits than its factorization.

21016612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5254157 (or 5254155 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 21016612 is about 4584.3878544469. The cubic root of 21016612 is about 275.9651464775.

Adding to 21016612 its reverse (21661012), we get a palindrome (42677624).

The spelling of 21016612 in words is "twenty-one million, sixteen thousand, six hundred twelve".