81738594261 has 8 divisors (see below), whose sum is σ = 121094213760. Its totient is φ = 54492396156.

The previous prime is 81738594241. The next prime is 81738594271. The reversal of 81738594261 is 16249583718.

81738594261 is a `hidden beast` number, since 8 + 17 + 38 + 594 + 2 + 6 + 1 = 666.

It is not a de Polignac number, because 81738594261 - 2⁹ = 81738593749 is a prime.

It is a super-2 number, since 2×81738594261² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81738594198 and 81738594207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81738594211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1513677645 + ... + 1513677698.

It is an arithmetic number, because the mean of its divisors is an integer number (15136776720).

Almost surely, 2^81738594261 is an apocalyptic number.

It is an amenable number.

81738594261 is a deficient number, since it is larger than the sum of its proper divisors (39355619499).

81738594261 is a wasteful number, since it uses less digits than its factorization.

81738594261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3027355352 (or 3027355346 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The spelling of 81738594261 in words is "eighty-one billion, seven hundred thirty-eight million, five hundred ninety-four thousand, two hundred sixty-one".