401989 has 4 divisors (see below), whose sum is σ = 459424. Its totient is φ = 344556.

The previous prime is 401987. The next prime is 401993. The reversal of 401989 is 989104.

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 a cyclic number.

It is not a de Polignac number, because 401989 - 2¹ = 401987 is a prime.

It is a super-2 number, since 2×401989² = 323190312242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 401989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401981) 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, 28707 + ... + 28720.

It is an arithmetic number, because the mean of its divisors is an integer number (114856).

2⁴⁰¹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

401989 is a deficient number, since it is larger than the sum of its proper divisors (57435).

401989 is an equidigital number, since it uses as much as digits as its factorization.

401989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57434.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 401989 is about 634.0260247025. The cubic root of 401989 is about 73.8025537511.

The spelling of 401989 in words is "four hundred one thousand, nine hundred eighty-nine".