400155 has 32 divisors (see below), whose sum is σ = 758784. Its totient is φ = 176256.

The previous prime is 400151. The next prime is 400157. The reversal of 400155 is 551004.

400155 = T₇₀ + T₇₁ + ... + T₁₃₉.

It is not a de Polignac number, because 400155 - 2² = 400151 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3834 + ... + 3936.

It is an arithmetic number, because the mean of its divisors is an integer number (23712).

2⁴⁰⁰¹⁵⁵ is an apocalyptic number.

400155 is a deficient number, since it is larger than the sum of its proper divisors (358629).

400155 is a wasteful number, since it uses less digits than its factorization.

400155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155.

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 400155 is about 632.5780584244. The cubic root of 400155 is about 73.6901458252.

Adding to 400155 its reverse (551004), we get a palindrome (951159).

It can be divided in two parts, 400 and 155, that added together give a palindrome (555).

The spelling of 400155 in words is "four hundred thousand, one hundred fifty-five".