81537756043 has 2 divisors, whose sum is σ = 81537756044. Its totient is φ = 81537756042.

The previous prime is 81537756023. The next prime is 81537756151. The reversal of 81537756043 is 34065773518.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81537756043 - 2²⁹ = 81000885131 is a prime.

It is not a weakly prime, because it can be changed into another prime (81537756023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40768878021 + 40768878022.

It is an arithmetic number, because the mean of its divisors is an integer number (40768878022).

Almost surely, 2^81537756043 is an apocalyptic number.

81537756043 is a deficient number, since it is larger than the sum of its proper divisors (1).

81537756043 is an equidigital number, since it uses as much as digits as its factorization.

81537756043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2116800, while the sum is 49.

The spelling of 81537756043 in words is "eighty-one billion, five hundred thirty-seven million, seven hundred fifty-six thousand, forty-three".