81120824197 has 32 divisors (see below), whose sum is σ = 99549620480. Its totient is φ = 64556974080.

The previous prime is 81120824173. The next prime is 81120824207. The reversal of 81120824197 is 79142802118.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81120824197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81120824297) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2229253 + ... + 2265349.

It is an arithmetic number, because the mean of its divisors is an integer number (3110925640).

Almost surely, 2^81120824197 is an apocalyptic number.

It is an amenable number.

81120824197 is a deficient number, since it is larger than the sum of its proper divisors (18428796283).

81120824197 is a wasteful number, since it uses less digits than its factorization.

81120824197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36461.

The product of its (nonzero) digits is 64512, while the sum is 43.

The spelling of 81120824197 in words is "eighty-one billion, one hundred twenty million, eight hundred twenty-four thousand, one hundred ninety-seven".