158539315981 has 4 divisors (see below), whose sum is σ = 160320656700. Its totient is φ = 156757975264.

The previous prime is 158539315967. The next prime is 158539316011. The reversal of 158539315981 is 189513935851.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 98511865956 + 60027450025 = 313866^2 + 245005^2 .

It is a cyclic number.

It is not a de Polignac number, because 158539315981 - 2⁹ = 158539315469 is a prime.

It is a super-3 number, since 3×158539315981³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (158539315901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 890670226 + ... + 890670403.

It is an arithmetic number, because the mean of its divisors is an integer number (40080164175).

Almost surely, 2^158539315981 is an apocalyptic number.

It is an amenable number.

158539315981 is a deficient number, since it is larger than the sum of its proper divisors (1781340719).

158539315981 is an equidigital number, since it uses as much as digits as its factorization.

158539315981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781340718.

The product of its digits is 5832000, while the sum is 58.

The spelling of 158539315981 in words is "one hundred fifty-eight billion, five hundred thirty-nine million, three hundred fifteen thousand, nine hundred eighty-one".