405841666 has 4 divisors (see below), whose sum is σ = 608762502. Its totient is φ = 202920832.

The previous prime is 405841661. The next prime is 405841669. The reversal of 405841666 is 666148504.

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., 377486041 + 28355625 = 19429^2 + 5325^2 .

It is not an unprimeable number, because it can be changed into a prime (405841661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101460415 + ... + 101460418.

Almost surely, 2^405841666 is an apocalyptic number.

405841666 is a deficient number, since it is larger than the sum of its proper divisors (202920836).

405841666 is a wasteful number, since it uses less digits than its factorization.

405841666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202920835.

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 405841666 is about 20145.5123042329. The cubic root of 405841666 is about 740.3757928159.

The spelling of 405841666 in words is "four hundred five million, eight hundred forty-one thousand, six hundred sixty-six".