81699352845 has 128 divisors (see below), whose sum is σ = 156213411840. Its totient is φ = 35997696000.

The previous prime is 81699352843. The next prime is 81699352859. The reversal of 81699352845 is 54825399618.

It is not a de Polignac number, because 81699352845 - 2¹ = 81699352843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81699352843) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 54867861 + ... + 54869349.

It is an arithmetic number, because the mean of its divisors is an integer number (1220417280).

Almost surely, 2^81699352845 is an apocalyptic number.

81699352845 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81699352845 is a deficient number, since it is larger than the sum of its proper divisors (74514058995).

81699352845 is a wasteful number, since it uses less digits than its factorization.

81699352845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2187.

The product of its digits is 18662400, while the sum is 60.

The spelling of 81699352845 in words is "eighty-one billion, six hundred ninety-nine million, three hundred fifty-two thousand, eight hundred forty-five".