81520367 has 2 divisors, whose sum is σ = 81520368. Its totient is φ = 81520366.

The previous prime is 81520333. The next prime is 81520379. The reversal of 81520367 is 76302518.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81520367 - 2²² = 77326063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81520267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40760183 + 40760184.

It is an arithmetic number, because the mean of its divisors is an integer number (40760184).

Almost surely, 2^81520367 is an apocalyptic number.

81520367 is a deficient number, since it is larger than the sum of its proper divisors (1).

81520367 is an equidigital number, since it uses as much as digits as its factorization.

81520367 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 81520367 is about 9028.8629959702. The cubic root of 81520367 is about 433.5994360971.

The spelling of 81520367 in words is "eighty-one million, five hundred twenty thousand, three hundred sixty-seven".