81940859434 has 32 divisors (see below), whose sum is σ = 144983093760. Its totient is φ = 34007017968.

The previous prime is 81940859411. The next prime is 81940859467. The reversal of 81940859434 is 43495804918.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 684972 + ... + 795655.

It is an arithmetic number, because the mean of its divisors is an integer number (4530721680).

Almost surely, 2^81940859434 is an apocalyptic number.

81940859434 is a deficient number, since it is larger than the sum of its proper divisors (63042234326).

81940859434 is a wasteful number, since it uses less digits than its factorization.

81940859434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1480762.

The product of its (nonzero) digits is 4976640, while the sum is 55.

The spelling of 81940859434 in words is "eighty-one billion, nine hundred forty million, eight hundred fifty-nine thousand, four hundred thirty-four".