126169991 has 2 divisors, whose sum is σ = 126169992. Its totient is φ = 126169990.

The previous prime is 126169961. The next prime is 126170017. The reversal of 126169991 is 199961621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 126169991 - 2¹⁴ = 126153607 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (126169921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63084995 + 63084996.

It is an arithmetic number, because the mean of its divisors is an integer number (63084996).

Almost surely, 2^126169991 is an apocalyptic number.

126169991 is a deficient number, since it is larger than the sum of its proper divisors (1).

126169991 is an equidigital number, since it uses as much as digits as its factorization.

126169991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52488, while the sum is 44.

The square root of 126169991 is about 11232.5416090928. The cubic root of 126169991 is about 501.5551460269. Note that the first 3 decimals are identical.

The spelling of 126169991 in words is "one hundred twenty-six million, one hundred sixty-nine thousand, nine hundred ninety-one".