66428616 has 64 divisors (see below), whose sum is σ = 171820800. Its totient is φ = 21385728.

The previous prime is 66428611. The next prime is 66428627. The reversal of 66428616 is 61682466.

It is a super-2 number, since 2×66428616² = 8825522047350912, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (66428611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 212076 + ... + 212388.

It is an arithmetic number, because the mean of its divisors is an integer number (2684700).

Almost surely, 2^66428616 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 66428616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85910400).

66428616 is an abundant number, since it is smaller than the sum of its proper divisors (105392184).

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

66428616 is a wasteful number, since it uses less digits than its factorization.

66428616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598 (or 594 counting only the distinct ones).

The product of its digits is 82944, while the sum is 39.

The square root of 66428616 is about 8150.3752060871. The cubic root of 66428616 is about 404.9969333711.

The spelling of 66428616 in words is "sixty-six million, four hundred twenty-eight thousand, six hundred sixteen".