81157353874 has 8 divisors (see below), whose sum is σ = 121744562508. Its totient is φ = 40575833040.

The previous prime is 81157353859. The next prime is 81157353877. The reversal of 81157353874 is 47835375118.

It can be written as a sum of positive squares in 2 ways, for example, as 60863357025 + 20293996849 = 246705^2 + 142457^2 .

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

It is not an unprimeable number, because it can be changed into a prime (81157353877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1386097 + ... + 1443460.

Almost surely, 2^81157353874 is an apocalyptic number.

81157353874 is a deficient number, since it is larger than the sum of its proper divisors (40587208634).

81157353874 is a wasteful number, since it uses less digits than its factorization.

81157353874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2843900.

The product of its digits is 2822400, while the sum is 52.

The spelling of 81157353874 in words is "eighty-one billion, one hundred fifty-seven million, three hundred fifty-three thousand, eight hundred seventy-four".