81312526739 has 2 divisors, whose sum is σ = 81312526740. Its totient is φ = 81312526738.

The previous prime is 81312526697. The next prime is 81312526747. The reversal of 81312526739 is 93762521318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81312526739 - 2¹⁶ = 81312461203 is a prime.

It is a super-2 number, since 2×81312526739² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81312526693 and 81312526702.

It is not a weakly prime, because it can be changed into another prime (81312526759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40656263369 + 40656263370.

It is an arithmetic number, because the mean of its divisors is an integer number (40656263370).

Almost surely, 2^81312526739 is an apocalyptic number.

81312526739 is a deficient number, since it is larger than the sum of its proper divisors (1).

81312526739 is an equidigital number, since it uses as much as digits as its factorization.

81312526739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 47.

The spelling of 81312526739 in words is "eighty-one billion, three hundred twelve million, five hundred twenty-six thousand, seven hundred thirty-nine".