81074725878 has 16 divisors (see below), whose sum is σ = 167380079616. Its totient is φ = 26153137320.

The previous prime is 81074725843. The next prime is 81074725889. The reversal of 81074725878 is 87852747018.

It is a super-2 number, since 2×81074725878² (a number of 23 digits) contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 217942626 + ... + 217942997.

It is an arithmetic number, because the mean of its divisors is an integer number (10461254976).

Almost surely, 2^81074725878 is an apocalyptic number.

81074725878 is an abundant number, since it is smaller than the sum of its proper divisors (86305353738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81074725878 is a wasteful number, since it uses less digits than its factorization.

81074725878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435885659.

The product of its (nonzero) digits is 7024640, while the sum is 57.

The spelling of 81074725878 in words is "eighty-one billion, seventy-four million, seven hundred twenty-five thousand, eight hundred seventy-eight".