338915991 has 4 divisors (see below), whose sum is σ = 451887992. Its totient is φ = 225943992.

The previous prime is 338915921. The next prime is 338916023. The reversal of 338915991 is 199519833.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199519833 = 3 ⋅66506611.

It is not a de Polignac number, because 338915991 - 2²³ = 330527383 is a prime.

It is a super-2 number, since 2×338915991² = 229728097911024162, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 338915991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (338915921) 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, 56485996 + ... + 56486001.

It is an arithmetic number, because the mean of its divisors is an integer number (112971998).

Almost surely, 2^338915991 is an apocalyptic number.

338915991 is a deficient number, since it is larger than the sum of its proper divisors (112972001).

338915991 is a wasteful number, since it uses less digits than its factorization.

338915991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112972000.

The product of its digits is 262440, while the sum is 48.

The square root of 338915991 is about 18409.6711268833. The cubic root of 338915991 is about 697.2106624859.

The spelling of 338915991 in words is "three hundred thirty-eight million, nine hundred fifteen thousand, nine hundred ninety-one".