400218031 has 2 divisors, whose sum is σ = 400218032. Its totient is φ = 400218030.

The previous prime is 400218017. The next prime is 400218043. The reversal of 400218031 is 130812004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400218031 - 2¹³ = 400209839 is a prime.

It is a super-2 number, since 2×400218031² = 320348944675033922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400212031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200109015 + 200109016.

It is an arithmetic number, because the mean of its divisors is an integer number (200109016).

Almost surely, 2^400218031 is an apocalyptic number.

400218031 is a deficient number, since it is larger than the sum of its proper divisors (1).

400218031 is an equidigital number, since it uses as much as digits as its factorization.

400218031 is an odious number, because the sum of its binary digits is odd.

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

The square root of 400218031 is about 20005.4500324287. The cubic root of 400218031 is about 736.9401475905.

The spelling of 400218031 in words is "four hundred million, two hundred eighteen thousand, thirty-one".