81899422545 has 8 divisors (see below), whose sum is σ = 131039076096. Its totient is φ = 43679692016.

The previous prime is 81899422543. The next prime is 81899422601. The reversal of 81899422545 is 54522499818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81899422545 - 2¹ = 81899422543 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81899422543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2729980737 + ... + 2729980766.

It is an arithmetic number, because the mean of its divisors is an integer number (16379884512).

Almost surely, 2^81899422545 is an apocalyptic number.

It is an amenable number.

81899422545 is a deficient number, since it is larger than the sum of its proper divisors (49139653551).

81899422545 is a wasteful number, since it uses less digits than its factorization.

81899422545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5459961511.

The product of its digits is 8294400, while the sum is 57.

The spelling of 81899422545 in words is "eighty-one billion, eight hundred ninety-nine million, four hundred twenty-two thousand, five hundred forty-five".