81845147578 has 8 divisors (see below), whose sum is σ = 122769953460. Its totient is φ = 40921829760.

The previous prime is 81845147563. The next prime is 81845147603. The reversal of 81845147578 is 87574154818.

It can be written as a sum of positive squares in 2 ways, for example, as 80989760569 + 855387009 = 284587^2 + 29247^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222493 + ... + 461728.

Almost surely, 2^81845147578 is an apocalyptic number.

81845147578 is a deficient number, since it is larger than the sum of its proper divisors (40924805882).

81845147578 is a wasteful number, since it uses less digits than its factorization.

81845147578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 744032.

The product of its digits is 10035200, while the sum is 58.

The spelling of 81845147578 in words is "eighty-one billion, eight hundred forty-five million, one hundred forty-seven thousand, five hundred seventy-eight".