81589544 has 16 divisors (see below), whose sum is σ = 153076500. Its totient is φ = 40769152.

The previous prime is 81589537. The next prime is 81589559. The reversal of 81589544 is 44598518.

It can be written as a sum of positive squares in 2 ways, for example, as 60996100 + 20593444 = 7810^2 + 4538^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81589495 and 81589504.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21932 + ... + 25380.

Almost surely, 2^81589544 is an apocalyptic number.

It is an amenable number.

81589544 is a deficient number, since it is larger than the sum of its proper divisors (71486956).

81589544 is a wasteful number, since it uses less digits than its factorization.

81589544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6412 (or 6408 counting only the distinct ones).

The product of its digits is 230400, while the sum is 44.

The square root of 81589544 is about 9032.6930646402. The cubic root of 81589544 is about 433.7220501497.

The spelling of 81589544 in words is "eighty-one million, five hundred eighty-nine thousand, five hundred forty-four".