81772342548 has 96 divisors (see below), whose sum is σ = 208494187776. Its totient is φ = 24792210432.

The previous prime is 81772342489. The next prime is 81772342559. The reversal of 81772342548 is 84524327718.

It is a happy number.

It is a super-2 number, since 2×81772342548² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81772342548.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14539665 + ... + 14545287.

It is an arithmetic number, because the mean of its divisors is an integer number (2171814456).

Almost surely, 2^81772342548 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81772342548, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104247093888).

81772342548 is an abundant number, since it is smaller than the sum of its proper divisors (126721845228).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81772342548 is a wasteful number, since it uses less digits than its factorization.

81772342548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6993 (or 6991 counting only the distinct ones).

The product of its digits is 3010560, while the sum is 51.

The spelling of 81772342548 in words is "eighty-one billion, seven hundred seventy-two million, three hundred forty-two thousand, five hundred forty-eight".