76999999991 has 4 divisors (see below), whose sum is σ = 77100130800. Its totient is φ = 76899869184.

The previous prime is 76999999981. The next prime is 77000000023. The reversal of 76999999991 is 19999999967.

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

It is a cyclic number.

It is not a de Polignac number, because 76999999991 - 2¹⁰ = 76999998967 is a prime.

It is a super-2 number, since 2×76999999991² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76999999981) 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, 50064251 + ... + 50065788.

It is an arithmetic number, because the mean of its divisors is an integer number (19275032700).

Almost surely, 2^76999999991 is an apocalyptic number.

76999999991 is a deficient number, since it is larger than the sum of its proper divisors (100130809).

76999999991 is a wasteful number, since it uses less digits than its factorization.

76999999991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100130808.

The product of its digits is 1807962282, while the sum is 86.

Adding to 76999999991 its sum of digits (86), we get a palindrome (77000000077).

The spelling of 76999999991 in words is "seventy-six billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-one".