666764442 has 24 divisors (see below), whose sum is σ = 1447217460. Its totient is φ = 221860800.

The previous prime is 666764393. The next prime is 666764453. The reversal of 666764442 is 244467666.

666764442 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 666724041 + 40401 = 25821^2 + 201^2 .

It is a super-2 number, since 2×666764442² = 889149642231142728, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22309 + ... + 42792.

Almost surely, 2^666764442 is an apocalyptic number.

666764442 is an abundant number, since it is smaller than the sum of its proper divisors (780453018).

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

666764442 is a wasteful number, since it uses less digits than its factorization.

666764442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65678 (or 65675 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 45.

The square root of 666764442 is about 25821.7823164862. The cubic root of 666764442 is about 873.6231699592.

The spelling of 666764442 in words is "six hundred sixty-six million, seven hundred sixty-four thousand, four hundred forty-two".