158981 has 2 divisors, whose sum is σ = 158982. Its totient is φ = 158980.

The previous prime is 158959. The next prime is 158993. The reversal of 158981 is 189851.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122500 + 36481 = 350^2 + 191^2 .

It is an emirp because it is prime and its reverse (189851) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-158981 is a prime.

It is a super-2 number, since 2×158981² = 50549916722, which contains 22 as substring.

It is a Sophie Germain prime.

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 158981.

It is not a weakly prime, because it can be changed into another prime (158941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79490 + 79491.

It is an arithmetic number, because the mean of its divisors is an integer number (79491).

2¹⁵⁸⁹⁸¹ is an apocalyptic number.

It is an amenable number.

158981 is a deficient number, since it is larger than the sum of its proper divisors (1).

158981 is an equidigital number, since it uses as much as digits as its factorization.

158981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 32.

The square root of 158981 is about 398.7242154673. The cubic root of 158981 is about 54.1728571492.

The spelling of 158981 in words is "one hundred fifty-eight thousand, nine hundred eighty-one".