81772342534 has 4 divisors (see below), whose sum is σ = 122658513804. Its totient is φ = 40886171266.

The previous prime is 81772342489. The next prime is 81772342559. The reversal of 81772342534 is 43524327718.

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

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, 20443085632 + ... + 20443085635.

It is an arithmetic number, because the mean of its divisors is an integer number (30664628451).

Almost surely, 2^81772342534 is an apocalyptic number.

81772342534 is a deficient number, since it is larger than the sum of its proper divisors (40886171270).

81772342534 is a wasteful number, since it uses less digits than its factorization.

81772342534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40886171269.

The product of its digits is 1128960, while the sum is 46.

The spelling of 81772342534 in words is "eighty-one billion, seven hundred seventy-two million, three hundred forty-two thousand, five hundred thirty-four".