81436913801 has 2 divisors, whose sum is σ = 81436913802. Its totient is φ = 81436913800.

The previous prime is 81436913759. The next prime is 81436913837. The reversal of 81436913801 is 10831963418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53789205625 + 27647708176 = 231925^2 + 166276^2 .

It is a cyclic number.

It is not a de Polignac number, because 81436913801 - 2¹⁴ = 81436897417 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (81436913891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40718456900 + 40718456901.

It is an arithmetic number, because the mean of its divisors is an integer number (40718456901).

Almost surely, 2^81436913801 is an apocalyptic number.

It is an amenable number.

81436913801 is a deficient number, since it is larger than the sum of its proper divisors (1).

81436913801 is an equidigital number, since it uses as much as digits as its factorization.

81436913801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 44.

The spelling of 81436913801 in words is "eighty-one billion, four hundred thirty-six million, nine hundred thirteen thousand, eight hundred one".