81734055646 has 4 divisors (see below), whose sum is σ = 122601083472. Its totient is φ = 40867027822.

The previous prime is 81734055631. The next prime is 81734055691. The reversal of 81734055646 is 64655043718.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 81734055646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20433513910 + ... + 20433513913.

It is an arithmetic number, because the mean of its divisors is an integer number (30650270868).

Almost surely, 2^81734055646 is an apocalyptic number.

81734055646 is a deficient number, since it is larger than the sum of its proper divisors (40867027826).

81734055646 is a wasteful number, since it uses less digits than its factorization.

81734055646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40867027825.

The product of its (nonzero) digits is 2419200, while the sum is 49.

The spelling of 81734055646 in words is "eighty-one billion, seven hundred thirty-four million, fifty-five thousand, six hundred forty-six".