402140209 has 4 divisors (see below), whose sum is σ = 403425316. Its totient is φ = 400855104.

The previous prime is 402140197. The next prime is 402140213. The reversal of 402140209 is 902041204.

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

It can be written as a sum of positive squares in 2 ways, for example, as 44930209 + 357210000 = 6703^2 + 18900^2 .

It is a cyclic number.

It is not a de Polignac number, because 402140209 - 2⁹ = 402139697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 402140209.

It is not an unprimeable number, because it can be changed into a prime (402120209) 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, 642084 + ... + 642709.

It is an arithmetic number, because the mean of its divisors is an integer number (100856329).

Almost surely, 2^402140209 is an apocalyptic number.

It is an amenable number.

402140209 is a deficient number, since it is larger than the sum of its proper divisors (1285107).

402140209 is a wasteful number, since it uses less digits than its factorization.

402140209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1285106.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 402140209 is about 20053.4338456036. The cubic root of 402140209 is about 738.1180625252.

The spelling of 402140209 in words is "four hundred two million, one hundred forty thousand, two hundred nine".