398826691 has 2 divisors, whose sum is σ = 398826692. Its totient is φ = 398826690.

The previous prime is 398826689. The next prime is 398826707. The reversal of 398826691 is 196628893.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 398826691 - 2¹ = 398826689 is a prime.

Together with 398826689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (398826641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199413345 + 199413346.

It is an arithmetic number, because the mean of its divisors is an integer number (199413346).

Almost surely, 2^398826691 is an apocalyptic number.

398826691 is a deficient number, since it is larger than the sum of its proper divisors (1).

398826691 is an equidigital number, since it uses as much as digits as its factorization.

398826691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 52.

The square root of 398826691 is about 19970.6457331755. The cubic root of 398826691 is about 736.0851762984.

The spelling of 398826691 in words is "three hundred ninety-eight million, eight hundred twenty-six thousand, six hundred ninety-one".