21002416 has 20 divisors (see below), whose sum is σ = 41461632. Its totient is φ = 10302656.

The previous prime is 21002413. The next prime is 21002431. The reversal of 21002416 is 61420012.

It is a super-2 number, since 2×21002416² = 882202955674112, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a self number, because there is not a number n which added to its sum of digits gives 21002416.

It is not an unprimeable number, because it can be changed into a prime (21002413) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11536 + ... + 13231.

Almost surely, 2^21002416 is an apocalyptic number.

It is an amenable number.

21002416 is a deficient number, since it is larger than the sum of its proper divisors (20459216).

21002416 is a wasteful number, since it uses less digits than its factorization.

21002416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24828 (or 24822 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21002416 is about 4582.8392945858. The cubic root of 21002416 is about 275.9029974876.

Adding to 21002416 its reverse (61420012), we get a palindrome (82422428).

The spelling of 21002416 in words is "twenty-one million, two thousand, four hundred sixteen".