398771691 has 4 divisors (see below), whose sum is σ = 531695592. Its totient is φ = 265847792.

The previous prime is 398771687. The next prime is 398771707. The reversal of 398771691 is 196177893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 196177893 = 3 ⋅65392631.

It is a cyclic number.

It is not a de Polignac number, because 398771691 - 2² = 398771687 is a prime.

It is not an unprimeable number, because it can be changed into a prime (398771651) 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, 66461946 + ... + 66461951.

It is an arithmetic number, because the mean of its divisors is an integer number (132923898).

Almost surely, 2^398771691 is an apocalyptic number.

398771691 is a deficient number, since it is larger than the sum of its proper divisors (132923901).

398771691 is a wasteful number, since it uses less digits than its factorization.

398771691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132923900.

The product of its digits is 571536, while the sum is 51.

The square root of 398771691 is about 19969.2686646257. The cubic root of 398771691 is about 736.0513382539.

The spelling of 398771691 in words is "three hundred ninety-eight million, seven hundred seventy-one thousand, six hundred ninety-one".