66128620 has 24 divisors (see below), whose sum is σ = 142624944. Its totient is φ = 25736256.

The previous prime is 66128603. The next prime is 66128627. The reversal of 66128620 is 2682166.

It is not an unprimeable number, because it can be changed into a prime (66128627) 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, 43942 + ... + 45421.

It is an arithmetic number, because the mean of its divisors is an integer number (5942706).

Almost surely, 2^66128620 is an apocalyptic number.

It is an amenable number.

66128620 is an abundant number, since it is smaller than the sum of its proper divisors (76496324).

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

66128620 is a wasteful number, since it uses less digits than its factorization.

66128620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89409 (or 89407 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 66128620 is about 8131.9505655162. The cubic root of 66128620 is about 404.3863490353.

The spelling of 66128620 in words is "sixty-six million, one hundred twenty-eight thousand, six hundred twenty".