400397666 has 4 divisors (see below), whose sum is σ = 600596502. Its totient is φ = 200198832.

The previous prime is 400397629. The next prime is 400397671. The reversal of 400397666 is 666793004.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 306985441 + 93412225 = 17521^2 + 9665^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100099415 + ... + 100099418.

Almost surely, 2^400397666 is an apocalyptic number.

400397666 is a deficient number, since it is larger than the sum of its proper divisors (200198836).

400397666 is a wasteful number, since it uses less digits than its factorization.

400397666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200198835.

The product of its (nonzero) digits is 163296, while the sum is 41.

The square root of 400397666 is about 20009.9391803174. The cubic root of 400397666 is about 737.0503878696.

The spelling of 400397666 in words is "four hundred million, three hundred ninety-seven thousand, six hundred sixty-six".