402391 has 8 divisors (see below), whose sum is σ = 443664. Its totient is φ = 361920.

The previous prime is 402383. The next prime is 402403. The reversal of 402391 is 193204.

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

It is a cyclic number.

It is not a de Polignac number, because 402391 - 2³ = 402383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1611 + ... + 1843.

It is an arithmetic number, because the mean of its divisors is an integer number (55458).

2⁴⁰²³⁹¹ is an apocalyptic number.

402391 is a deficient number, since it is larger than the sum of its proper divisors (41273).

402391 is a wasteful number, since it uses less digits than its factorization.

402391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 402391 is about 634.3429671715. The cubic root of 402391 is about 73.8271470793.

Adding to 402391 its reverse (193204), we get a palindrome (595595).

It can be divided in two parts, 4023 and 91, that added together give a palindrome (4114).

The spelling of 402391 in words is "four hundred two thousand, three hundred ninety-one".