81126049 has 3 divisors (see below), whose sum is σ = 81135057. Its totient is φ = 81117042.

The previous prime is 81126043. The next prime is 81126061. The reversal of 81126049 is 94062118.

It is a happy number.

The square root of 81126049 is 9007.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 81126049 - 2³ = 81126041 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81126049.

It is not an unprimeable number, because it can be changed into a prime (81126041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4504 + ... + 13510.

It is an arithmetic number, because the mean of its divisors is an integer number (27045019).

Almost surely, 2^81126049 is an apocalyptic number.

81126049 is the 9007-th square number.

81126049 is the 4504-th centered octagonal number.

It is an amenable number.

81126049 is a deficient number, since it is larger than the sum of its proper divisors (9008).

81126049 is an frugal number, since it uses more digits than its factorization.

81126049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18014 (or 9007 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The cubic root of 81126049 is about 432.8991919530.

It can be divided in two parts, 8112 and 6049, that added together give a square (14161 = 119²).

The spelling of 81126049 in words is "eighty-one million, one hundred twenty-six thousand, forty-nine".