66128790 has 64 divisors (see below), whose sum is σ = 195342336. Its totient is φ = 13951872.

The previous prime is 66128747. The next prime is 66128791. The reversal of 66128790 is 9782166.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66128791) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9382 + ... + 14841.

It is an arithmetic number, because the mean of its divisors is an integer number (3052224).

Almost surely, 2^66128790 is an apocalyptic number.

66128790 is an abundant number, since it is smaller than the sum of its proper divisors (129213546).

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

66128790 is a wasteful number, since it uses less digits than its factorization.

66128790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24253.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 66128790 is about 8131.9610181063. The cubic root of 66128790 is about 404.3866955601.

The spelling of 66128790 in words is "sixty-six million, one hundred twenty-eight thousand, seven hundred ninety".