666738783 has 24 divisors (see below), whose sum is σ = 1009990800. Its totient is φ = 439483968.

The previous prime is 666738773. The next prime is 666738803. The reversal of 666738783 is 387837666.

It is not a de Polignac number, because 666738783 - 2⁶ = 666738719 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666738733) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6213 + ... + 37041.

It is an arithmetic number, because the mean of its divisors is an integer number (42082950).

Almost surely, 2^666738783 is an apocalyptic number.

666738783 is a deficient number, since it is larger than the sum of its proper divisors (343252017).

666738783 is an equidigital number, since it uses as much as digits as its factorization.

666738783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30933 (or 30921 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 54.

The square root of 666738783 is about 25821.2854637410. The cubic root of 666738783 is about 873.6119633105.

The spelling of 666738783 in words is "six hundred sixty-six million, seven hundred thirty-eight thousand, seven hundred eighty-three".