81588212 has 12 divisors (see below), whose sum is σ = 143393796. Its totient is φ = 40618560.

The previous prime is 81588203. The next prime is 81588217. The reversal of 81588212 is 21288518.

It can be written as a sum of positive squares in 2 ways, for example, as 25847056 + 55741156 = 5084^2 + 7466^2 .

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81588217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42839 + ... + 44702.

It is an arithmetic number, because the mean of its divisors is an integer number (11949483).

Almost surely, 2^81588212 is an apocalyptic number.

It is an amenable number.

81588212 is a deficient number, since it is larger than the sum of its proper divisors (61805584).

81588212 is a wasteful number, since it uses less digits than its factorization.

81588212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87778 (or 87776 counting only the distinct ones).

The product of its digits is 10240, while the sum is 35.

The square root of 81588212 is about 9032.6193321760. The cubic root of 81588212 is about 433.7196898762.

The spelling of 81588212 in words is "eighty-one million, five hundred eighty-eight thousand, two hundred twelve".