81217368780 has 24 divisors (see below), whose sum is σ = 227408632752. Its totient is φ = 21657964992.

The previous prime is 81217368779. The next prime is 81217368797. The reversal of 81217368780 is 8786371218.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 676811347 + ... + 676811466.

It is an arithmetic number, because the mean of its divisors is an integer number (9475359698).

Almost surely, 2^81217368780 is an apocalyptic number.

It is an amenable number.

81217368780 is an abundant number, since it is smaller than the sum of its proper divisors (146191263972).

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

81217368780 is a wasteful number, since it uses less digits than its factorization.

81217368780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1353622825 (or 1353622823 counting only the distinct ones).

The product of its (nonzero) digits is 903168, while the sum is 51.

The spelling of 81217368780 in words is "eighty-one billion, two hundred seventeen million, three hundred sixty-eight thousand, seven hundred eighty".