81380648554 has 16 divisors (see below), whose sum is σ = 122737628160. Its totient is φ = 40468201840.

The previous prime is 81380648549. The next prime is 81380648579. The reversal of 81380648554 is 45584608318.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1878267 + ... + 1921105.

It is an arithmetic number, because the mean of its divisors is an integer number (7671101760).

Almost surely, 2^81380648554 is an apocalyptic number.

81380648554 is a deficient number, since it is larger than the sum of its proper divisors (41356979606).

81380648554 is a wasteful number, since it uses less digits than its factorization.

81380648554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48005.

The product of its (nonzero) digits is 3686400, while the sum is 52.

The spelling of 81380648554 in words is "eighty-one billion, three hundred eighty million, six hundred forty-eight thousand, five hundred fifty-four".