81781016494 has 8 divisors (see below), whose sum is σ = 129127920840. Its totient is φ = 38738376216.

The previous prime is 81781016477. The next prime is 81781016501. The reversal of 81781016494 is 49461018718.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1076065969 + ... + 1076066044.

It is an arithmetic number, because the mean of its divisors is an integer number (16140990105).

Almost surely, 2^81781016494 is an apocalyptic number.

81781016494 is a deficient number, since it is larger than the sum of its proper divisors (47346904346).

81781016494 is a wasteful number, since it uses less digits than its factorization.

81781016494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2152132034.

The product of its (nonzero) digits is 387072, while the sum is 49.

The spelling of 81781016494 in words is "eighty-one billion, seven hundred eighty-one million, sixteen thousand, four hundred ninety-four".