81895539 has 16 divisors (see below), whose sum is σ = 119643264. Its totient is φ = 49416000.

The previous prime is 81895537. The next prime is 81895559. The reversal of 81895539 is 93559818.

It is not a de Polignac number, because 81895539 - 2¹ = 81895537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81895537) 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, 2364 + ... + 13014.

It is an arithmetic number, because the mean of its divisors is an integer number (7477704).

Almost surely, 2^81895539 is an apocalyptic number.

81895539 is a deficient number, since it is larger than the sum of its proper divisors (37747725).

81895539 is a wasteful number, since it uses less digits than its factorization.

81895539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10898.

The product of its digits is 388800, while the sum is 48.

The square root of 81895539 is about 9049.6154061927. The cubic root of 81895539 is about 434.2635868980.

The spelling of 81895539 in words is "eighty-one million, eight hundred ninety-five thousand, five hundred thirty-nine".