400993 has 4 divisors (see below), whose sum is σ = 402948. Its totient is φ = 399040.

The previous prime is 400963. The next prime is 400997. The reversal of 400993 is 399004.

400993 is nontrivially palindromic in base 8.

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

It can be written as a sum of positive squares in 2 ways, for example, as 186624 + 214369 = 432^2 + 463^2 .

It is a cyclic number.

It is not a de Polignac number, because 400993 - 2⁹ = 400481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400997) 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, 628 + ... + 1093.

It is an arithmetic number, because the mean of its divisors is an integer number (100737).

2⁴⁰⁰⁹⁹³ is an apocalyptic number.

It is an amenable number.

400993 is a deficient number, since it is larger than the sum of its proper divisors (1955).

400993 is a wasteful number, since it uses less digits than its factorization.

400993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1954.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 400993 is about 633.2400808540. The cubic root of 400993 is about 73.7415503103.

Adding to 400993 its reverse (399004), we get a palindrome (799997).

The spelling of 400993 in words is "four hundred thousand, nine hundred ninety-three".