402491 has 4 divisors (see below), whose sum is σ = 416400. Its totient is φ = 388584.

The previous prime is 402487. The next prime is 402503. The reversal of 402491 is 194204.

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

It is a cyclic number.

It is not a de Polignac number, because 402491 - 2² = 402487 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 402491.

It is not an unprimeable number, because it can be changed into a prime (402091) 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, 6911 + ... + 6968.

It is an arithmetic number, because the mean of its divisors is an integer number (104100).

2⁴⁰²⁴⁹¹ is an apocalyptic number.

402491 is a deficient number, since it is larger than the sum of its proper divisors (13909).

402491 is a wasteful number, since it uses less digits than its factorization.

402491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13908.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 402491 is about 634.4217839892. The cubic root of 402491 is about 73.8332622784.

Adding to 402491 its reverse (194204), we get a palindrome (596695).

The spelling of 402491 in words is "four hundred two thousand, four hundred ninety-one".