66613616 has 40 divisors (see below), whose sum is σ = 140370480. Its totient is φ = 30495744.

The previous prime is 66613583. The next prime is 66613619. The reversal of 66613616 is 61631666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66613619) 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, 6755 + ... + 13373.

It is an arithmetic number, because the mean of its divisors is an integer number (3509262).

Almost surely, 2^66613616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66613616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70185240).

66613616 is an abundant number, since it is smaller than the sum of its proper divisors (73756864).

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

66613616 is a wasteful number, since it uses less digits than its factorization.

66613616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6681 (or 6675 counting only the distinct ones).

The product of its digits is 23328, while the sum is 35.

The square root of 66613616 is about 8161.7164861321. The cubic root of 66613616 is about 405.3725495394.

The spelling of 66613616 in words is "sixty-six million, six hundred thirteen thousand, six hundred sixteen".