400019 has 4 divisors (see below), whose sum is σ = 401544. Its totient is φ = 398496.

The previous prime is 400009. The next prime is 400031. The reversal of 400019 is 910004.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400019 is a prime.

It is a super-2 number, since 2×400019² = 320030400722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 399976 and 400012.

It is not an unprimeable number, because it can be changed into a prime (400009) 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, 257 + ... + 930.

It is an arithmetic number, because the mean of its divisors is an integer number (100386).

2⁴⁰⁰⁰¹⁹ is an apocalyptic number.

400019 is a deficient number, since it is larger than the sum of its proper divisors (1525).

400019 is a wasteful number, since it uses less digits than its factorization.

400019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1524.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 400019 is about 632.4705526742. The cubic root of 400019 is about 73.6817965643.

The spelling of 400019 in words is "four hundred thousand, nineteen".