81907777750 has 32 divisors (see below), whose sum is σ = 154764413856. Its totient is φ = 32456903200.

The previous prime is 81907777739. The next prime is 81907777759. The reversal of 81907777750 is 5777770918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81907777759) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1504237 + ... + 1557736.

It is an arithmetic number, because the mean of its divisors is an integer number (4836387933).

Almost surely, 2^81907777750 is an apocalyptic number.

81907777750 is a deficient number, since it is larger than the sum of its proper divisors (72856636106).

81907777750 is a wasteful number, since it uses less digits than its factorization.

81907777750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3062097 (or 3062087 counting only the distinct ones).

The product of its (nonzero) digits is 6050520, while the sum is 58.

The spelling of 81907777750 in words is "eighty-one billion, nine hundred seven million, seven hundred seventy-seven thousand, seven hundred fifty".