126666691 has 8 divisors (see below), whose sum is σ = 129938864. Its totient is φ = 123409440.

The previous prime is 126666679. The next prime is 126666721. The reversal of 126666691 is 196666621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 126666691 - 2⁷ = 126666563 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (126666601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14605 + ... + 21601.

It is an arithmetic number, because the mean of its divisors is an integer number (16242358).

Almost surely, 2^126666691 is an apocalyptic number.

126666691 is a deficient number, since it is larger than the sum of its proper divisors (3272173).

126666691 is an equidigital number, since it uses as much as digits as its factorization.

126666691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7461.

The product of its digits is 139968, while the sum is 43.

The square root of 126666691 is about 11254.6297584594. The cubic root of 126666691 is about 502.2124503538.

The spelling of 126666691 in words is "one hundred twenty-six million, six hundred sixty-six thousand, six hundred ninety-one".