81348839045 has 18 divisors (see below), whose sum is σ = 98223092982. Its totient is φ = 64678554816.

The previous prime is 81348839041. The next prime is 81348839051. The reversal of 81348839045 is 54093884318.

It can be written as a sum of positive squares in 9 ways, for example, as 14014297924 + 67334541121 = 118382^2 + 259489^2 .

It is not a de Polignac number, because 81348839045 - 2² = 81348839041 is a prime.

It is a super-2 number, since 2×81348839045² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81348839041) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 146047907 + ... + 146048463.

It is an arithmetic number, because the mean of its divisors is an integer number (5456838499).

Almost surely, 2^81348839045 is an apocalyptic number.

It is an amenable number.

81348839045 is a deficient number, since it is larger than the sum of its proper divisors (16874253937).

81348839045 is an frugal number, since it uses more digits than its factorization.

81348839045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1577 (or 791 counting only the distinct ones).

The product of its (nonzero) digits is 3317760, while the sum is 53.

The spelling of 81348839045 in words is "eighty-one billion, three hundred forty-eight million, eight hundred thirty-nine thousand, forty-five".