81158149 has 2 divisors, whose sum is σ = 81158150. Its totient is φ = 81158148.

The previous prime is 81158141. The next prime is 81158171. The reversal of 81158149 is 94185118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60062500 + 21095649 = 7750^2 + 4593^2 .

It is a cyclic number.

It is not a de Polignac number, because 81158149 - 2³ = 81158141 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81158141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40579074 + 40579075.

It is an arithmetic number, because the mean of its divisors is an integer number (40579075).

Almost surely, 2^81158149 is an apocalyptic number.

It is an amenable number.

81158149 is a deficient number, since it is larger than the sum of its proper divisors (1).

81158149 is an equidigital number, since it uses as much as digits as its factorization.

81158149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 37.

The square root of 81158149 is about 9008.7817711386. The cubic root of 81158149 is about 432.9562810214.

The spelling of 81158149 in words is "eighty-one million, one hundred fifty-eight thousand, one hundred forty-nine".