400023181 has 2 divisors, whose sum is σ = 400023182. Its totient is φ = 400023180.

The previous prime is 400023161. The next prime is 400023223. The reversal of 400023181 is 181320004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 349129225 + 50893956 = 18685^2 + 7134^2 .

It is a cyclic number.

It is not a de Polignac number, because 400023181 - 2⁹ = 400022669 is a prime.

It is a super-3 number, since 3×400023181³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400023161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200011590 + 200011591.

It is an arithmetic number, because the mean of its divisors is an integer number (200011591).

Almost surely, 2^400023181 is an apocalyptic number.

It is an amenable number.

400023181 is a deficient number, since it is larger than the sum of its proper divisors (1).

400023181 is an equidigital number, since it uses as much as digits as its factorization.

400023181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 400023181 is about 20000.5795166040. The cubic root of 400023181 is about 736.8205327088.

Adding to 400023181 its reverse (181320004), we get a palindrome (581343185).

The spelling of 400023181 in words is "four hundred million, twenty-three thousand, one hundred eighty-one".