126991171 has 2 divisors, whose sum is σ = 126991172. Its totient is φ = 126991170.

The previous prime is 126991147. The next prime is 126991223. The reversal of 126991171 is 171199621.

It is a weak prime.

It is an emirp because it is prime and its reverse (171199621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 126991171 - 2²³ = 118602563 is a prime.

It is a super-2 number, since 2×126991171² = 32253515023902482, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 126991171.

It is not a weakly prime, because it can be changed into another prime (126991121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63495585 + 63495586.

It is an arithmetic number, because the mean of its divisors is an integer number (63495586).

Almost surely, 2^126991171 is an apocalyptic number.

126991171 is a deficient number, since it is larger than the sum of its proper divisors (1).

126991171 is an equidigital number, since it uses as much as digits as its factorization.

126991171 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804, while the sum is 37.

The square root of 126991171 is about 11269.0359392452. The cubic root of 126991171 is about 502.6409211786.

The spelling of 126991171 in words is "one hundred twenty-six million, nine hundred ninety-one thousand, one hundred seventy-one".