699999999999991 has 2 divisors, whose sum is σ = 699999999999992. Its totient is φ = 699999999999990.

The previous prime is 699999999999953. The next prime is 700000000000051. The reversal of 699999999999991 is 199999999999996.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 699999999999991 - 2⁷ = 699999999999863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (699999999999901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 349999999999995 + 349999999999996.

It is an arithmetic number, because the mean of its divisors is an integer number (349999999999996).

Almost surely, 2^{699999999999991} is an apocalyptic number.

699999999999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

699999999999991 is an equidigital number, since it uses as much as digits as its factorization.

699999999999991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15251194969974, while the sum is 124.

The spelling of 699999999999991 in words is "six hundred ninety-nine trillion, nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-one".