158815381 has 2 divisors, whose sum is σ = 158815382. Its totient is φ = 158815380.

The previous prime is 158815379. The next prime is 158815403. The reversal of 158815381 is 183518851.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87142225 + 71673156 = 9335^2 + 8466^2 .

It is a cyclic number.

It is not a de Polignac number, because 158815381 - 2¹ = 158815379 is a prime.

It is a super-2 number, since 2×158815381² = 50444650484350322, which contains 22 as substring.

Together with 158815379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (158815351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79407690 + 79407691.

It is an arithmetic number, because the mean of its divisors is an integer number (79407691).

Almost surely, 2^158815381 is an apocalyptic number.

It is an amenable number.

158815381 is a deficient number, since it is larger than the sum of its proper divisors (1).

158815381 is an equidigital number, since it uses as much as digits as its factorization.

158815381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38400, while the sum is 40.

The square root of 158815381 is about 12602.1974671087. The cubic root of 158815381 is about 541.5403902668.

The spelling of 158815381 in words is "one hundred fifty-eight million, eight hundred fifteen thousand, three hundred eighty-one".