158187681 has 8 divisors (see below), whose sum is σ = 234352160. Its totient is φ = 105458436.

The previous prime is 158187677. The next prime is 158187719. The reversal of 158187681 is 186781851.

158187681 is a `hidden beast` number, since 1 + 581 + 8 + 7 + 68 + 1 = 666.

It is not a de Polignac number, because 158187681 - 2² = 158187677 is a prime.

It is a super-2 number, since 2×158187681² = 50046684840315522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (158187671) 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, 2929375 + ... + 2929428.

It is an arithmetic number, because the mean of its divisors is an integer number (29294020).

Almost surely, 2^158187681 is an apocalyptic number.

It is an amenable number.

158187681 is a deficient number, since it is larger than the sum of its proper divisors (76164479).

158187681 is an equidigital number, since it uses as much as digits as its factorization.

158187681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5858812 (or 5858806 counting only the distinct ones).

The product of its digits is 107520, while the sum is 45.

The square root of 158187681 is about 12577.2684236284. The cubic root of 158187681 is about 540.8259890018.

The spelling of 158187681 in words is "one hundred fifty-eight million, one hundred eighty-seven thousand, six hundred eighty-one".