33991138387 has 4 divisors (see below), whose sum is σ = 33991509280. Its totient is φ = 33990767496.

The previous prime is 33991138319. The next prime is 33991138403. The reversal of 33991138387 is 78383119933.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 78383119933 = 41 ⋅1911783413.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-33991138387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (33991133387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62758 + ... + 268180.

It is an arithmetic number, because the mean of its divisors is an integer number (8497877320).

Almost surely, 2^33991138387 is an apocalyptic number.

33991138387 is a deficient number, since it is larger than the sum of its proper divisors (370893).

33991138387 is a wasteful number, since it uses less digits than its factorization.

33991138387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370892.

The product of its digits is 2939328, while the sum is 55.

The spelling of 33991138387 in words is "thirty-three billion, nine hundred ninety-one million, one hundred thirty-eight thousand, three hundred eighty-seven".