81326587 has 2 divisors, whose sum is σ = 81326588. Its totient is φ = 81326586.

The previous prime is 81326573. The next prime is 81326621. The reversal of 81326587 is 78562318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81326587 - 2¹¹ = 81324539 is a prime.

It is a super-2 number, since 2×81326587² = 13228027506137138, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81326387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40663293 + 40663294.

It is an arithmetic number, because the mean of its divisors is an integer number (40663294).

Almost surely, 2^81326587 is an apocalyptic number.

81326587 is a deficient number, since it is larger than the sum of its proper divisors (1).

81326587 is an equidigital number, since it uses as much as digits as its factorization.

81326587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 80640, while the sum is 40.

The square root of 81326587 is about 9018.1254704068. The cubic root of 81326587 is about 433.2555974298.

The spelling of 81326587 in words is "eighty-one million, three hundred twenty-six thousand, five hundred eighty-seven".