398661157 has 2 divisors, whose sum is σ = 398661158. Its totient is φ = 398661156.

The previous prime is 398661149. The next prime is 398661187. The reversal of 398661157 is 751166893.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 248819076 + 149842081 = 15774^2 + 12241^2 .

It is an emirp because it is prime and its reverse (751166893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398661157 - 2³ = 398661149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398661187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199330578 + 199330579.

It is an arithmetic number, because the mean of its divisors is an integer number (199330579).

Almost surely, 2^398661157 is an apocalyptic number.

It is an amenable number.

398661157 is a deficient number, since it is larger than the sum of its proper divisors (1).

398661157 is an equidigital number, since it uses as much as digits as its factorization.

398661157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 46.

The square root of 398661157 is about 19966.5008702076. The cubic root of 398661157 is about 735.9833242175.

The spelling of 398661157 in words is "three hundred ninety-eight million, six hundred sixty-one thousand, one hundred fifty-seven".