81277544723420 has 96 divisors (see below), whose sum is σ = 176707229529600. Its totient is φ = 31365288864000.

The previous prime is 81277544723393. The next prime is 81277544723491. The reversal of 81277544723420 is 2432744577218.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4348476275 + ... + 4348494965.

It is an arithmetic number, because the mean of its divisors is an integer number (1840700307600).

Almost surely, 2^{81277544723420} is an apocalyptic number.

It is an amenable number.

81277544723420 is an abundant number, since it is smaller than the sum of its proper divisors (95429684806180).

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

81277544723420 is a wasteful number, since it uses less digits than its factorization.

81277544723420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24219 (or 24217 counting only the distinct ones).

The product of its (nonzero) digits is 21073920, while the sum is 56.

The spelling of 81277544723420 in words is "eighty-one trillion, two hundred seventy-seven billion, five hundred forty-four million, seven hundred twenty-three thousand, four hundred twenty".