158191666 has 16 divisors (see below), whose sum is σ = 241770240. Its totient is φ = 77608080.

The previous prime is 158191651. The next prime is 158191669. The reversal of 158191666 is 666191851.

It is not an unprimeable number, because it can be changed into a prime (158191669) 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 in 7 ways as a sum of consecutive naturals, for example, 57085 + ... + 59791.

It is an arithmetic number, because the mean of its divisors is an integer number (15110640).

Almost surely, 2^158191666 is an apocalyptic number.

158191666 is a deficient number, since it is larger than the sum of its proper divisors (83578574).

158191666 is a wasteful number, since it uses less digits than its factorization.

158191666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3249.

The product of its digits is 77760, while the sum is 43.

The square root of 158191666 is about 12577.4268433571. The cubic root of 158191666 is about 540.8305303868.

The spelling of 158191666 in words is "one hundred fifty-eight million, one hundred ninety-one thousand, six hundred sixty-six".