81940859435 has 16 divisors (see below), whose sum is σ = 104238770400. Its totient is φ = 61622171136.

The previous prime is 81940859411. The next prime is 81940859467. The reversal of 81940859435 is 53495804918.

It is a cyclic number.

It is not a de Polignac number, because 81940859435 - 2²⁸ = 81672423979 is a prime.

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, 510965 + ... + 651894.

It is an arithmetic number, because the mean of its divisors is an integer number (6514923150).

Almost surely, 2^81940859435 is an apocalyptic number.

81940859435 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81940859435 is a deficient number, since it is larger than the sum of its proper divisors (22297910965).

81940859435 is a wasteful number, since it uses less digits than its factorization.

81940859435 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1163710.

The product of its (nonzero) digits is 6220800, while the sum is 56.

The spelling of 81940859435 in words is "eighty-one billion, nine hundred forty million, eight hundred fifty-nine thousand, four hundred thirty-five".