81481481554 has 24 divisors (see below), whose sum is σ = 135532359900. Its totient is φ = 36709263360.

The previous prime is 81481481527. The next prime is 81481481597. The reversal of 81481481554 is 45518418418.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 59124354025 + 22357127529 = 243155^2 + 149523^2 .

It is a super-3 number, since 3×81481481554³ (a number of 34 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81481481498 and 81481481507.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1462479 + ... + 1517170.

Almost surely, 2^81481481554 is an apocalyptic number.

81481481554 is a deficient number, since it is larger than the sum of its proper divisors (54050878346).

81481481554 is a wasteful number, since it uses less digits than its factorization.

81481481554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2979786 (or 2979775 counting only the distinct ones).

The product of its digits is 819200, while the sum is 49.

The spelling of 81481481554 in words is "eighty-one billion, four hundred eighty-one million, four hundred eighty-one thousand, five hundred fifty-four".