1398117591 has 40 divisors (see below), whose sum is σ = 2253114864. Its totient is φ = 858885120.

The previous prime is 1398117559. The next prime is 1398117599. The reversal of 1398117591 is 1957118931.

It is a happy number.

1398117591 is a `hidden beast` number, since 1 + 398 + 1 + 175 + 91 = 666.

It is not a de Polignac number, because 1398117591 - 2⁵ = 1398117559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398117599) 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 39 ways as a sum of consecutive naturals, for example, 1148215 + ... + 1149431.

Almost surely, 2^1398117591 is an apocalyptic number.

1398117591 is a deficient number, since it is larger than the sum of its proper divisors (854997273).

1398117591 is a wasteful number, since it uses less digits than its factorization.

1398117591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333 (or 2324 counting only the distinct ones).

The product of its digits is 68040, while the sum is 45.

The square root of 1398117591 is about 37391.4106580642. The cubic root of 1398117591 is about 1118.1873290681.

The spelling of 1398117591 in words is "one billion, three hundred ninety-eight million, one hundred seventeen thousand, five hundred ninety-one".