81738473797 has 4 divisors (see below), whose sum is σ = 81761290240. Its totient is φ = 81715657356.

The previous prime is 81738473753. The next prime is 81738473809. The reversal of 81738473797 is 79737483718.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81738473797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81738473737) 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, 11402847 + ... + 11410012.

It is an arithmetic number, because the mean of its divisors is an integer number (20440322560).

Almost surely, 2^81738473797 is an apocalyptic number.

It is an amenable number.

81738473797 is a deficient number, since it is larger than the sum of its proper divisors (22816443).

81738473797 is a wasteful number, since it uses less digits than its factorization.

81738473797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22816442.

The product of its digits is 49787136, while the sum is 64.

The spelling of 81738473797 in words is "eighty-one billion, seven hundred thirty-eight million, four hundred seventy-three thousand, seven hundred ninety-seven".