81157734619 has 8 divisors (see below), whose sum is σ = 89762817200. Its totient is φ = 72890106336.

The previous prime is 81157734587. The next prime is 81157734629. The reversal of 81157734619 is 91643775118.

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 81157734619 - 2⁵ = 81157734587 is a prime.

It is a super-2 number, since 2×81157734619² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81157734629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84363069 + ... + 84364030.

It is an arithmetic number, because the mean of its divisors is an integer number (11220352150).

Almost surely, 2^81157734619 is an apocalyptic number.

81157734619 is a deficient number, since it is larger than the sum of its proper divisors (8605082581).

81157734619 is a wasteful number, since it uses less digits than its factorization.

81157734619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168727149.

The product of its digits is 1270080, while the sum is 52.

The spelling of 81157734619 in words is "eighty-one billion, one hundred fifty-seven million, seven hundred thirty-four thousand, six hundred nineteen".