400025 has 6 divisors (see below), whose sum is σ = 496062. Its totient is φ = 320000.

The previous prime is 400009. The next prime is 400031. The reversal of 400025 is 520004.

It can be written as a sum of positive squares in 3 ways, for example, as 73984 + 326041 = 272^2 + 571^2 .

It is a sliding number, since 400025 = 25 + 400000 and 1/25 + 1/400000 = 0.0400025.

It is not a de Polignac number, because 400025 - 2⁴ = 400009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 399979 and 400015.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7976 + ... + 8025.

It is an arithmetic number, because the mean of its divisors is an integer number (82677).

2⁴⁰⁰⁰²⁵ is an apocalyptic number.

It is an amenable number.

400025 is a deficient number, since it is larger than the sum of its proper divisors (96037).

400025 is a wasteful number, since it uses less digits than its factorization.

400025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16011 (or 16006 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 11.

The square root of 400025 is about 632.4752959602. The cubic root of 400025 is about 73.6821649540.

Adding to 400025 its product of nonzero digits (40), we get a triangular number (400065 = T₈₉₄).

Adding to 400025 its reverse (520004), we get a palindrome (920029).

It can be divided in two parts, 4000 and 25, that multiplied together give a 5-th power (100000 = 10⁵).

The spelling of 400025 in words is "four hundred thousand, twenty-five".