81567049 has 2 divisors, whose sum is σ = 81567050. Its totient is φ = 81567048.

The previous prime is 81567023. The next prime is 81567077. The reversal of 81567049 is 94076518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67765824 + 13801225 = 8232^2 + 3715^2 .

It is a cyclic number.

It is not a de Polignac number, because 81567049 - 2²⁵ = 48012617 is a prime.

It is not a weakly prime, because it can be changed into another prime (81567089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40783524 + 40783525.

It is an arithmetic number, because the mean of its divisors is an integer number (40783525).

Almost surely, 2^81567049 is an apocalyptic number.

It is an amenable number.

81567049 is a deficient number, since it is larger than the sum of its proper divisors (1).

81567049 is an equidigital number, since it uses as much as digits as its factorization.

81567049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 81567049 is about 9031.4477798413. The cubic root of 81567049 is about 433.6821860779.

The spelling of 81567049 in words is "eighty-one million, five hundred sixty-seven thousand, forty-nine".