126156991 has 2 divisors, whose sum is σ = 126156992. Its totient is φ = 126156990.

The previous prime is 126156971. The next prime is 126156997. The reversal of 126156991 is 199651621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 126156991 - 2¹⁷ = 126025919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (126156997) 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, 63078495 + 63078496.

It is an arithmetic number, because the mean of its divisors is an integer number (63078496).

Almost surely, 2^126156991 is an apocalyptic number.

126156991 is a deficient number, since it is larger than the sum of its proper divisors (1).

126156991 is an equidigital number, since it uses as much as digits as its factorization.

126156991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29160, while the sum is 40.

The square root of 126156991 is about 11231.9629183861. The cubic root of 126156991 is about 501.5379194244.

The spelling of 126156991 in words is "one hundred twenty-six million, one hundred fifty-six thousand, nine hundred ninety-one".