81858003671 has 2 divisors, whose sum is σ = 81858003672. Its totient is φ = 81858003670.

The previous prime is 81858003641. The next prime is 81858003709. The reversal of 81858003671 is 17630085818.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81858003671 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81858003641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40929001835 + 40929001836.

It is an arithmetic number, because the mean of its divisors is an integer number (40929001836).

Almost surely, 2^81858003671 is an apocalyptic number.

81858003671 is a deficient number, since it is larger than the sum of its proper divisors (1).

81858003671 is an equidigital number, since it uses as much as digits as its factorization.

81858003671 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 322560, while the sum is 47.

The spelling of 81858003671 in words is "eighty-one billion, eight hundred fifty-eight million, three thousand, six hundred seventy-one".