81539211 has 8 divisors (see below), whose sum is σ = 117082000. Its totient is φ = 50177952.

The previous prime is 81539189. The next prime is 81539251. The reversal of 81539211 is 11293518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81539211 - 2⁵ = 81539179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81539251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1045336 + ... + 1045413.

It is an arithmetic number, because the mean of its divisors is an integer number (14635250).

Almost surely, 2^81539211 is an apocalyptic number.

81539211 is a deficient number, since it is larger than the sum of its proper divisors (35542789).

81539211 is a wasteful number, since it uses less digits than its factorization.

81539211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2090765.

The product of its digits is 2160, while the sum is 30.

The square root of 81539211 is about 9029.9064779210. The cubic root of 81539211 is about 433.6328433652.

The spelling of 81539211 in words is "eighty-one million, five hundred thirty-nine thousand, two hundred eleven".