401999 has 12 divisors (see below), whose sum is σ = 464184. Its totient is φ = 345984.

The previous prime is 401993. The next prime is 402023. The reversal of 401999 is 999104.

401999 = T₆₀ + T₆₁ + ... + T₁₃₇.

It is not a de Polignac number, because 401999 - 2⁸ = 401743 is a prime.

It is a Duffinian number.

401999 is a modest number, since divided by 999 gives 401 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3704 + ... + 3810.

It is an arithmetic number, because the mean of its divisors is an integer number (38682).

2⁴⁰¹⁹⁹⁹ is an apocalyptic number.

401999 is a deficient number, since it is larger than the sum of its proper divisors (62185).

401999 is a wasteful number, since it uses less digits than its factorization.

401999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 401999 is about 634.0339107650. The cubic root of 401999 is about 73.8031657242.

The spelling of 401999 in words is "four hundred one thousand, nine hundred ninety-nine".