1157199991 has 2 divisors, whose sum is σ = 1157199992. Its totient is φ = 1157199990.

The previous prime is 1157199889. The next prime is 1157200003. The reversal of 1157199991 is 1999917511.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1157199991 - 2⁹ = 1157199479 is a prime.

It is a super-2 number, since 2×1157199991² = 2678223638340800162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1157199091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 578599995 + 578599996.

It is an arithmetic number, because the mean of its divisors is an integer number (578599996).

Almost surely, 2^1157199991 is an apocalyptic number.

1157199991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1157199991 is an equidigital number, since it uses as much as digits as its factorization.

1157199991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 229635, while the sum is 52.

The square root of 1157199991 is about 34017.6423492281. The cubic root of 1157199991 is about 1049.8714857073.

The spelling of 1157199991 in words is "one billion, one hundred fifty-seven million, one hundred ninety-nine thousand, nine hundred ninety-one".