81298958205720 has 64 divisors (see below), whose sum is σ = 258243749601120. Its totient is φ = 20404444411904.

The previous prime is 81298958205713. The next prime is 81298958205757. The reversal of 81298958205720 is 2750285989218.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19926213207 + ... + 19926217286.

Almost surely, 2^{81298958205720} is an apocalyptic number.

It is an amenable number.

81298958205720 is an abundant number, since it is smaller than the sum of its proper divisors (176944791395400).

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

81298958205720 is a wasteful number, since it uses less digits than its factorization.

81298958205720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39852430524 (or 39852430520 counting only the distinct ones).

The product of its (nonzero) digits is 58060800, while the sum is 66.

The spelling of 81298958205720 in words is "eighty-one trillion, two hundred ninety-eight billion, nine hundred fifty-eight million, two hundred five thousand, seven hundred twenty".