398667491 has 4 divisors (see below), whose sum is σ = 407938872. Its totient is φ = 389396112.

The previous prime is 398667473. The next prime is 398667517. The reversal of 398667491 is 194766893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194766893 = 31 ⋅6282803.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398667491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398667091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4635626 + ... + 4635711.

It is an arithmetic number, because the mean of its divisors is an integer number (101984718).

Almost surely, 2^398667491 is an apocalyptic number.

398667491 is a deficient number, since it is larger than the sum of its proper divisors (9271381).

398667491 is an equidigital number, since it uses as much as digits as its factorization.

398667491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9271380.

The product of its digits is 1959552, while the sum is 53.

The square root of 398667491 is about 19966.6594852519. The cubic root of 398667491 is about 735.9872220086.

The spelling of 398667491 in words is "three hundred ninety-eight million, six hundred sixty-seven thousand, four hundred ninety-one".