1991153699 has 2 divisors, whose sum is σ = 1991153700. Its totient is φ = 1991153698.

The previous prime is 1991153687. The next prime is 1991153711. The reversal of 1991153699 is 9963511991.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1991153687) and next prime (1991153711).

It is a cyclic number.

It is not a de Polignac number, because 1991153699 - 2⁸ = 1991153443 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1991153699.

It is not a weakly prime, because it can be changed into another prime (1991153639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995576849 + 995576850.

It is an arithmetic number, because the mean of its divisors is an integer number (995576850).

Almost surely, 2^1991153699 is an apocalyptic number.

1991153699 is a deficient number, since it is larger than the sum of its proper divisors (1).

1991153699 is an equidigital number, since it uses as much as digits as its factorization.

1991153699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 590490, while the sum is 53.

The square root of 1991153699 is about 44622.3452879832. The cubic root of 1991153699 is about 1258.0606975127.

The spelling of 1991153699 in words is "one billion, nine hundred ninety-one million, one hundred fifty-three thousand, six hundred ninety-nine".