81816838450 has 48 divisors (see below), whose sum is σ = 154095449760. Its totient is φ = 32316635520.

The previous prime is 81816838447. The next prime is 81816838469. The reversal of 81816838450 is 5483861818.

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, 1650121 + ... + 1698979.

It is an arithmetic number, because the mean of its divisors is an integer number (3210321870).

Almost surely, 2^81816838450 is an apocalyptic number.

81816838450 is a deficient number, since it is larger than the sum of its proper divisors (72278611310).

81816838450 is a wasteful number, since it uses less digits than its factorization.

81816838450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49291 (or 49286 counting only the distinct ones).

The product of its (nonzero) digits is 1474560, while the sum is 52.

The spelling of 81816838450 in words is "eighty-one billion, eight hundred sixteen million, eight hundred thirty-eight thousand, four hundred fifty".