81536269 has 2 divisors, whose sum is σ = 81536270. Its totient is φ = 81536268.

The previous prime is 81536183. The next prime is 81536291. The reversal of 81536269 is 96263518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80460900 + 1075369 = 8970^2 + 1037^2 .

It is a cyclic number.

It is not a de Polignac number, because 81536269 - 2⁷ = 81536141 is a prime.

It is a super-2 number, since 2×81536269² = 13296326324880722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81536069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40768134 + 40768135.

It is an arithmetic number, because the mean of its divisors is an integer number (40768135).

Almost surely, 2^81536269 is an apocalyptic number.

It is an amenable number.

81536269 is a deficient number, since it is larger than the sum of its proper divisors (1).

81536269 is an equidigital number, since it uses as much as digits as its factorization.

81536269 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 40.

The square root of 81536269 is about 9029.7435733248. The cubic root of 81536269 is about 433.6276280291.

The spelling of 81536269 in words is "eighty-one million, five hundred thirty-six thousand, two hundred sixty-nine".