81292550464 has 28 divisors (see below), whose sum is σ = 161381139264. Its totient is φ = 40629586304.

The previous prime is 81292550441. The next prime is 81292550467. The reversal of 81292550464 is 46405529218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81292550467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102934 + ... + 416149.

Almost surely, 2^81292550464 is an apocalyptic number.

It is an amenable number.

81292550464 is a deficient number, since it is larger than the sum of its proper divisors (80088588800).

81292550464 is a wasteful number, since it uses less digits than its factorization.

81292550464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521542 (or 521532 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 46.

The spelling of 81292550464 in words is "eighty-one billion, two hundred ninety-two million, five hundred fifty thousand, four hundred sixty-four".