402209 has 4 divisors (see below), whose sum is σ = 405504. Its totient is φ = 398916.

The previous prime is 402197. The next prime is 402221. The reversal of 402209 is 902204.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (402197) and next prime (402221).

It is a cyclic number.

It is not a de Polignac number, because 402209 - 2⁸ = 401953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (402239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1457 + ... + 1710.

It is an arithmetic number, because the mean of its divisors is an integer number (101376).

2⁴⁰²²⁰⁹ is an apocalyptic number.

It is an amenable number.

402209 is a deficient number, since it is larger than the sum of its proper divisors (3295).

402209 is a wasteful number, since it uses less digits than its factorization.

402209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3294.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 402209 is about 634.1994954271. The cubic root of 402209 is about 73.8160148166.

The spelling of 402209 in words is "four hundred two thousand, two hundred nine".