1398185911 has 4 divisors (see below), whose sum is σ = 1398458632. Its totient is φ = 1397913192.

The previous prime is 1398185909. The next prime is 1398185917. The reversal of 1398185911 is 1195818931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1195818931 = 83 ⋅14407457.

It is a cyclic number.

It is not a de Polignac number, because 1398185911 - 2¹ = 1398185909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398185917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128520 + ... + 138973.

It is an arithmetic number, because the mean of its divisors is an integer number (349614658).

Almost surely, 2^1398185911 is an apocalyptic number.

1398185911 is a deficient number, since it is larger than the sum of its proper divisors (272721).

1398185911 is an equidigital number, since it uses as much as digits as its factorization.

1398185911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272720.

The product of its digits is 77760, while the sum is 46.

The square root of 1398185911 is about 37392.3242257017. The cubic root of 1398185911 is about 1118.2055424417.

The spelling of 1398185911 in words is "one billion, three hundred ninety-eight million, one hundred eighty-five thousand, nine hundred eleven".