398131231 has 2 divisors, whose sum is σ = 398131232. Its totient is φ = 398131230.

The previous prime is 398131229. The next prime is 398131243. The reversal of 398131231 is 132131893.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 398131231 - 2¹ = 398131229 is a prime.

It is a super-2 number, since 2×398131231² = 317016954195150722, which contains 22 as substring.

Together with 398131229, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 398131193 and 398131202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398131831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199065615 + 199065616.

It is an arithmetic number, because the mean of its divisors is an integer number (199065616).

Almost surely, 2^398131231 is an apocalyptic number.

398131231 is a deficient number, since it is larger than the sum of its proper divisors (1).

398131231 is an equidigital number, since it uses as much as digits as its factorization.

398131231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 31.

The square root of 398131231 is about 19953.2260800102. The cubic root of 398131231 is about 735.6570741915.

The spelling of 398131231 in words is "three hundred ninety-eight million, one hundred thirty-one thousand, two hundred thirty-one".