400251 has 4 divisors (see below), whose sum is σ = 533672. Its totient is φ = 266832.

The previous prime is 400249. The next prime is 400261. The reversal of 400251 is 152004.

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

It is not a de Polignac number, because 400251 - 2¹ = 400249 is a prime.

It is a D-number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 400251.

It is not an unprimeable number, because it can be changed into a prime (400261) 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, 66706 + ... + 66711.

It is an arithmetic number, because the mean of its divisors is an integer number (133418).

2⁴⁰⁰²⁵¹ is an apocalyptic number.

400251 is a deficient number, since it is larger than the sum of its proper divisors (133421).

400251 is a wasteful number, since it uses less digits than its factorization.

400251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133420.

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 400251 is about 632.6539338374. The cubic root of 400251 is about 73.6960382821.

Adding to 400251 its reverse (152004), we get a palindrome (552255).

The spelling of 400251 in words is "four hundred thousand, two hundred fifty-one".