81436913759 has 2 divisors, whose sum is σ = 81436913760. Its totient is φ = 81436913758.

The previous prime is 81436913687. The next prime is 81436913801. The reversal of 81436913759 is 95731963418.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81436913759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81436613759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40718456879 + 40718456880.

It is an arithmetic number, because the mean of its divisors is an integer number (40718456880).

Almost surely, 2^81436913759 is an apocalyptic number.

81436913759 is a deficient number, since it is larger than the sum of its proper divisors (1).

81436913759 is an equidigital number, since it uses as much as digits as its factorization.

81436913759 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4898880, while the sum is 56.

The spelling of 81436913759 in words is "eighty-one billion, four hundred thirty-six million, nine hundred thirteen thousand, seven hundred fifty-nine".