405994 has 8 divisors (see below), whose sum is σ = 644868. Its totient is φ = 191040.

The previous prime is 405991. The next prime is 405997. The reversal of 405994 is 499504.

405994 = 63² + 64² + ... + 113².

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (405991) and next prime (405997).

It can be written as a sum of positive squares in 2 ways, for example, as 405769 + 225 = 637^2 + 15^2 .

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

It is a super-2 number, since 2×405994² = 329662256072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (405991) 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, 5937 + ... + 6004.

2⁴⁰⁵⁹⁹⁴ is an apocalyptic number.

405994 is a deficient number, since it is larger than the sum of its proper divisors (238874).

405994 is a wasteful number, since it uses less digits than its factorization.

405994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11960.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 405994 is about 637.1765846294. The cubic root of 405994 is about 74.0468415389.

The spelling of 405994 in words is "four hundred five thousand, nine hundred ninety-four".