666402407 has 4 divisors (see below), whose sum is σ = 726984456. Its totient is φ = 605820360.

The previous prime is 666402383. The next prime is 666402419. The reversal of 666402407 is 704204666.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666402407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666402307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30291008 + ... + 30291029.

It is an arithmetic number, because the mean of its divisors is an integer number (181746114).

Almost surely, 2^666402407 is an apocalyptic number.

666402407 is a deficient number, since it is larger than the sum of its proper divisors (60582049).

666402407 is a wasteful number, since it uses less digits than its factorization.

666402407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60582048.

The product of its (nonzero) digits is 48384, while the sum is 35.

The square root of 666402407 is about 25814.7711010576. The cubic root of 666402407 is about 873.4650234405.

The spelling of 666402407 in words is "six hundred sixty-six million, four hundred two thousand, four hundred seven".