81539049 has 16 divisors (see below), whose sum is σ = 110028672. Its totient is φ = 53708928.

The previous prime is 81539047. The next prime is 81539063. The reversal of 81539049 is 94093518.

It is not a de Polignac number, because 81539049 - 2¹ = 81539047 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81538998 and 81539016.

It is not an unprimeable number, because it can be changed into a prime (81539047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109372 + ... + 110114.

It is an arithmetic number, because the mean of its divisors is an integer number (6876792).

Almost surely, 2^81539049 is an apocalyptic number.

It is an amenable number.

81539049 is a deficient number, since it is larger than the sum of its proper divisors (28489623).

81539049 is a wasteful number, since it uses less digits than its factorization.

81539049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 81539049 is about 9029.8975077240. The cubic root of 81539049 is about 433.6325561882.

The spelling of 81539049 in words is "eighty-one million, five hundred thirty-nine thousand, forty-nine".