81037670081 has 2 divisors, whose sum is σ = 81037670082. Its totient is φ = 81037670080.

The previous prime is 81037670041. The next prime is 81037670111. The reversal of 81037670081 is 18007673018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64711219456 + 16326450625 = 254384^2 + 127775^2 .

It is a cyclic number.

It is not a de Polignac number, because 81037670081 - 2¹⁰ = 81037669057 is a prime.

It is a super-2 number, since 2×81037670081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81037670041) 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, 40518835040 + 40518835041.

It is an arithmetic number, because the mean of its divisors is an integer number (40518835041).

Almost surely, 2^81037670081 is an apocalyptic number.

It is an amenable number.

81037670081 is a deficient number, since it is larger than the sum of its proper divisors (1).

81037670081 is an equidigital number, since it uses as much as digits as its factorization.

81037670081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 41.

The spelling of 81037670081 in words is "eighty-one billion, thirty-seven million, six hundred seventy thousand, eighty-one".