1959999991 has 2 divisors, whose sum is σ = 1959999992. Its totient is φ = 1959999990.

The previous prime is 1959999971. The next prime is 1960000019. The reversal of 1959999991 is 1999999591.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1959999991 - 2⁷ = 1959999863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1959999991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1959999911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 979999995 + 979999996.

It is an arithmetic number, because the mean of its divisors is an integer number (979999996).

Almost surely, 2^1959999991 is an apocalyptic number.

1959999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1959999991 is an equidigital number, since it uses as much as digits as its factorization.

1959999991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23914845, while the sum is 70.

The square root of 1959999991 is about 44271.8871407127. The cubic root of 1959999991 is about 1251.4649472197.

It can be divided in two parts, 195999999 and 1, that added together give a square (196000000 = 14000²).

The spelling of 1959999991 in words is "one billion, nine hundred fifty-nine million, nine hundred ninety-nine thousand, nine hundred ninety-one".