81162549 has 12 divisors (see below), whose sum is σ = 126253036. Its totient is φ = 49946112.

The previous prime is 81162541. The next prime is 81162553. The reversal of 81162549 is 94526118.

It can be written as a sum of positive squares in 2 ways, for example, as 51022449 + 30140100 = 7143^2 + 5490^2 .

It is not a de Polignac number, because 81162549 - 2³ = 81162541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81162541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 346732 + ... + 346965.

Almost surely, 2^81162549 is an apocalyptic number.

It is an amenable number.

81162549 is a deficient number, since it is larger than the sum of its proper divisors (45090487).

81162549 is a wasteful number, since it uses less digits than its factorization.

81162549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693716 (or 693713 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 81162549 is about 9009.0259739885. The cubic root of 81162549 is about 432.9641051410.

The spelling of 81162549 in words is "eighty-one million, one hundred sixty-two thousand, five hundred forty-nine".