21010616 has 32 divisors (see below), whose sum is σ = 44463600. Its totient is φ = 9219840.

The previous prime is 21010609. The next prime is 21010663. The reversal of 21010616 is 61601012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21010594 and 21010603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1565 + ... + 6668.

Almost surely, 2^21010616 is an apocalyptic number.

It is an amenable number.

21010616 is an abundant number, since it is smaller than the sum of its proper divisors (23452984).

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

21010616 is a wasteful number, since it uses less digits than its factorization.

21010616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8279 (or 8275 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 21010616 is about 4583.7338491671. The cubic root of 21010616 is about 275.9388998684.

Adding to 21010616 its reverse (61601012), we get a palindrome (82611628).

The spelling of 21010616 in words is "twenty-one million, ten thousand, six hundred sixteen".