66021616 has 40 divisors (see below), whose sum is σ = 132218720. Its totient is φ = 31912704.

The previous prime is 66021611. The next prime is 66021629. The reversal of 66021616 is 61612066.

It is a super-3 number, since 3×66021616³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66021611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135325 + ... + 135811.

It is an arithmetic number, because the mean of its divisors is an integer number (3305468).

Almost surely, 2^66021616 is an apocalyptic number.

It is an amenable number.

66021616 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

66021616 is a wasteful number, since it uses less digits than its factorization.

66021616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761 (or 755 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 66021616 is about 8125.3686685590. The cubic root of 66021616 is about 404.1681161578.

The spelling of 66021616 in words is "sixty-six million, twenty-one thousand, six hundred sixteen".