81654239277 has 24 divisors (see below), whose sum is σ = 127032305400. Its totient is φ = 50242987008.

The previous prime is 81654239243. The next prime is 81654239281. The reversal of 81654239277 is 77293245618.

It is a happy number.

81654239277 is a `hidden beast` number, since 8 + 1 + 6 + 542 + 3 + 92 + 7 + 7 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 12593552841 + 69060686436 = 112221^2 + 262794^2 .

It is not a de Polignac number, because 81654239277 - 2⁸ = 81654239021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81654239287) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1126549 + ... + 1196837.

It is an arithmetic number, because the mean of its divisors is an integer number (5293012725).

Almost surely, 2^81654239277 is an apocalyptic number.

It is an amenable number.

81654239277 is a deficient number, since it is larger than the sum of its proper divisors (45378066123).

81654239277 is a wasteful number, since it uses less digits than its factorization.

81654239277 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80237 (or 80234 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 54.

The spelling of 81654239277 in words is "eighty-one billion, six hundred fifty-four million, two hundred thirty-nine thousand, two hundred seventy-seven".