749999999991 has 16 divisors (see below), whose sum is σ = 1090923821568. Its totient is φ = 454539316800.

The previous prime is 749999999989. The next prime is 750000000031. The reversal of 749999999991 is 199999999947.

It is not a de Polignac number, because 749999999991 - 2¹ = 749999999989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 749999999895 and 749999999904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (749999999921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4028931 + ... + 4210971.

It is an arithmetic number, because the mean of its divisors is an integer number (68182738848).

Almost surely, 2^749999999991 is an apocalyptic number.

749999999991 is a deficient number, since it is larger than the sum of its proper divisors (340923821577).

749999999991 is a wasteful number, since it uses less digits than its factorization.

749999999991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306902.

The product of its digits is 10847773692, while the sum is 93.

The spelling of 749999999991 in words is "seven hundred forty-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-one".