398884861 has 2 divisors, whose sum is σ = 398884862. Its totient is φ = 398884860.

The previous prime is 398884847. The next prime is 398884891. The reversal of 398884861 is 168488893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 372721636 + 26163225 = 19306^2 + 5115^2 .

It is a cyclic number.

It is not a de Polignac number, because 398884861 - 2⁹ = 398884349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398884831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199442430 + 199442431.

It is an arithmetic number, because the mean of its divisors is an integer number (199442431).

Almost surely, 2^398884861 is an apocalyptic number.

It is an amenable number.

398884861 is a deficient number, since it is larger than the sum of its proper divisors (1).

398884861 is an equidigital number, since it uses as much as digits as its factorization.

398884861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2654208, while the sum is 55.

The square root of 398884861 is about 19972.1020676342. The cubic root of 398884861 is about 736.1209612597.

The spelling of 398884861 in words is "three hundred ninety-eight million, eight hundred eighty-four thousand, eight hundred sixty-one".