1157901991 has 2 divisors, whose sum is σ = 1157901992. Its totient is φ = 1157901990.

The previous prime is 1157901967. The next prime is 1157902003. The reversal of 1157901991 is 1991097511.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1157901991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1157901931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 578950995 + 578950996.

It is an arithmetic number, because the mean of its divisors is an integer number (578950996).

Almost surely, 2^1157901991 is an apocalyptic number.

1157901991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1157901991 is an equidigital number, since it uses as much as digits as its factorization.

1157901991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25515, while the sum is 43.

The square root of 1157901991 is about 34027.9589602433. The cubic root of 1157901991 is about 1050.0837396555.

The spelling of 1157901991 in words is "one billion, one hundred fifty-seven million, nine hundred one thousand, nine hundred ninety-one".