81371955650 has 48 divisors (see below), whose sum is σ = 151910753280. Its totient is φ = 32428771200.

The previous prime is 81371955647. The next prime is 81371955683. The reversal of 81371955650 is 5655917318.

It is a Harshad number since it is a multiple of its sum of digits (50).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32276390 + ... + 32278910.

It is an arithmetic number, because the mean of its divisors is an integer number (3164807360).

Almost surely, 2^81371955650 is an apocalyptic number.

81371955650 is a deficient number, since it is larger than the sum of its proper divisors (70538797630).

81371955650 is a wasteful number, since it uses less digits than its factorization.

81371955650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4659 (or 4654 counting only the distinct ones).

The product of its (nonzero) digits is 1134000, while the sum is 50.

The spelling of 81371955650 in words is "eighty-one billion, three hundred seventy-one million, nine hundred fifty-five thousand, six hundred fifty".