1991153711 has 2 divisors, whose sum is σ = 1991153712. Its totient is φ = 1991153710.

The previous prime is 1991153699. The next prime is 1991153719. The reversal of 1991153711 is 1173511991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1991153711 - 2¹⁰ = 1991152687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1991153719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995576855 + 995576856.

It is an arithmetic number, because the mean of its divisors is an integer number (995576856).

Almost surely, 2^1991153711 is an apocalyptic number.

1991153711 is a deficient number, since it is larger than the sum of its proper divisors (1).

1991153711 is an equidigital number, since it uses as much as digits as its factorization.

1991153711 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8505, while the sum is 38.

The square root of 1991153711 is about 44622.3454224450. The cubic root of 1991153711 is about 1258.0607000400.

The spelling of 1991153711 in words is "one billion, nine hundred ninety-one million, one hundred fifty-three thousand, seven hundred eleven".