402640306 has 8 divisors (see below), whose sum is σ = 604074780. Its totient is φ = 201282048.

The previous prime is 402640297. The next prime is 402640309. The reversal of 402640306 is 603046204.

It can be written as a sum of positive squares in 2 ways, for example, as 386712225 + 15928081 = 19665^2 + 3991^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (402640309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3211 + ... + 28558.

Almost surely, 2^402640306 is an apocalyptic number.

402640306 is a deficient number, since it is larger than the sum of its proper divisors (201434474).

402640306 is a wasteful number, since it uses less digits than its factorization.

402640306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38108.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 402640306 is about 20065.8990827722. The cubic root of 402640306 is about 738.4239075270.

The spelling of 402640306 in words is "four hundred two million, six hundred forty thousand, three hundred six".