81472639 has 2 divisors, whose sum is σ = 81472640. Its totient is φ = 81472638.

The previous prime is 81472613. The next prime is 81472663. The reversal of 81472639 is 93627418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81472639 - 2⁷ = 81472511 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 (81472609) 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, 40736319 + 40736320.

It is an arithmetic number, because the mean of its divisors is an integer number (40736320).

Almost surely, 2^81472639 is an apocalyptic number.

81472639 is a deficient number, since it is larger than the sum of its proper divisors (1).

81472639 is an equidigital number, since it uses as much as digits as its factorization.

81472639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 40.

The square root of 81472639 is about 9026.2195297921. The cubic root of 81472639 is about 433.5147992768.

The spelling of 81472639 in words is "eighty-one million, four hundred seventy-two thousand, six hundred thirty-nine".