81734611583 has 4 divisors (see below), whose sum is σ = 83473645920. Its totient is φ = 79995577248.

The previous prime is 81734611579. The next prime is 81734611591. The reversal of 81734611583 is 38511643718.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 38511643718 = 2 ⋅19255821859.

It is a cyclic number.

It is not a de Polignac number, because 81734611583 - 2² = 81734611579 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 1739034289 = 81734611583 / (8 + 1 + 7 + 3 + 4 + 6 + 1 + 1 + 5 + 8 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81734611573) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 869517098 + ... + 869517191.

It is an arithmetic number, because the mean of its divisors is an integer number (20868411480).

Almost surely, 2^81734611583 is an apocalyptic number.

81734611583 is a deficient number, since it is larger than the sum of its proper divisors (1739034337).

81734611583 is a wasteful number, since it uses less digits than its factorization.

81734611583 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739034336.

The product of its digits is 483840, while the sum is 47.

The spelling of 81734611583 in words is "eighty-one billion, seven hundred thirty-four million, six hundred eleven thousand, five hundred eighty-three".