81849549099 has 16 divisors (see below), whose sum is σ = 110828518272. Its totient is φ = 53724731328.

The previous prime is 81849549077. The next prime is 81849549139. The reversal of 81849549099 is 99094594818.

It is not a de Polignac number, because 81849549099 - 2⁷ = 81849548971 is a prime.

It is a super-2 number, since 2×81849549099² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81849549029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 729834 + ... + 834479.

It is an arithmetic number, because the mean of its divisors is an integer number (6926782392).

Almost surely, 2^81849549099 is an apocalyptic number.

81849549099 is a deficient number, since it is larger than the sum of its proper divisors (28978969173).

81849549099 is a wasteful number, since it uses less digits than its factorization.

81849549099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564586.

The product of its (nonzero) digits is 33592320, while the sum is 66.

The spelling of 81849549099 in words is "eighty-one billion, eight hundred forty-nine million, five hundred forty-nine thousand, ninety-nine".