666777740 has 48 divisors (see below), whose sum is σ = 1522698912. Its totient is φ = 244233216.

The previous prime is 666777721. The next prime is 666777779. The reversal of 666777740 is 47777666.

It is a happy number.

It is a super-3 number, since 3×666777740³ (a number of 27 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13922 + ... + 39081.

It is an arithmetic number, because the mean of its divisors is an integer number (31722894).

Almost surely, 2^666777740 is an apocalyptic number.

It is an amenable number.

666777740 is an abundant number, since it is smaller than the sum of its proper divisors (855921172).

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

666777740 is a wasteful number, since it uses less digits than its factorization.

666777740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53066 (or 53064 counting only the distinct ones).

The product of its (nonzero) digits is 2074464, while the sum is 50.

The square root of 666777740 is about 25822.0398109832. The cubic root of 666777740 is about 873.6289777892.

The spelling of 666777740 in words is "six hundred sixty-six million, seven hundred seventy-seven thousand, seven hundred forty".