81698903843 has 4 divisors (see below), whose sum is σ = 81699477888. Its totient is φ = 81698329800.

The previous prime is 81698903809. The next prime is 81698903851. The reversal of 81698903843 is 34830989618.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 81698903843 - 2¹⁰ = 81698902819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81698906843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104318 + ... + 417468.

It is an arithmetic number, because the mean of its divisors is an integer number (20424869472).

Almost surely, 2^81698903843 is an apocalyptic number.

81698903843 is a deficient number, since it is larger than the sum of its proper divisors (574045).

81698903843 is a wasteful number, since it uses less digits than its factorization.

81698903843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574044.

The product of its (nonzero) digits is 8957952, while the sum is 59.

The spelling of 81698903843 in words is "eighty-one billion, six hundred ninety-eight million, nine hundred three thousand, eight hundred forty-three".