158131021 has 2 divisors, whose sum is σ = 158131022. Its totient is φ = 158131020.

The previous prime is 158130989. The next prime is 158131037. The reversal of 158131021 is 120131851.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95942025 + 62188996 = 9795^2 + 7886^2 .

It is a cyclic number.

It is not a de Polignac number, because 158131021 - 2⁵ = 158130989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 158130983 and 158131001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (158131621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79065510 + 79065511.

It is an arithmetic number, because the mean of its divisors is an integer number (79065511).

Almost surely, 2^158131021 is an apocalyptic number.

It is an amenable number.

158131021 is a deficient number, since it is larger than the sum of its proper divisors (1).

158131021 is an equidigital number, since it uses as much as digits as its factorization.

158131021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 22.

The square root of 158131021 is about 12575.0157455170. The cubic root of 158131021 is about 540.7614098899.

Adding to 158131021 its reverse (120131851), we get a palindrome (278262872).

The spelling of 158131021 in words is "one hundred fifty-eight million, one hundred thirty-one thousand, twenty-one".