666402406 has 4 divisors (see below), whose sum is σ = 999603612. Its totient is φ = 333201202.

The previous prime is 666402383. The next prime is 666402419. The reversal of 666402406 is 604204666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166600600 + ... + 166600603.

It is an arithmetic number, because the mean of its divisors is an integer number (249900903).

Almost surely, 2^666402406 is an apocalyptic number.

666402406 is a deficient number, since it is larger than the sum of its proper divisors (333201206).

666402406 is a wasteful number, since it uses less digits than its factorization.

666402406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333201205.

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 666402406 is about 25814.7710816889. The cubic root of 666402406 is about 873.4650230036.

The spelling of 666402406 in words is "six hundred sixty-six million, four hundred two thousand, four hundred six".