747999991 has 4 divisors (see below), whose sum is σ = 752589112. Its totient is φ = 743410872.

The previous prime is 747999977. The next prime is 748000013. The reversal of 747999991 is 199999747.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-747999991 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 (747999911) 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, 2294316 + ... + 2294641.

It is an arithmetic number, because the mean of its divisors is an integer number (188147278).

Almost surely, 2^747999991 is an apocalyptic number.

747999991 is a deficient number, since it is larger than the sum of its proper divisors (4589121).

747999991 is a wasteful number, since it uses less digits than its factorization.

747999991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4589120.

The product of its digits is 11573604, while the sum is 64.

The square root of 747999991 is about 27349.5884978184. The cubic root of 747999991 is about 907.7519646828.

The spelling of 747999991 in words is "seven hundred forty-seven million, nine hundred ninety-nine thousand, nine hundred ninety-one".