81211268 has 6 divisors (see below), whose sum is σ = 142119726. Its totient is φ = 40605632.

The previous prime is 81211237. The next prime is 81211297. The reversal of 81211268 is 86211218.

It can be written as a sum of positive squares in only one way, i.e., 46895104 + 34316164 = 6848^2 + 5858^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81211268.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10151405 + ... + 10151412.

It is an arithmetic number, because the mean of its divisors is an integer number (23686621).

Almost surely, 2^81211268 is an apocalyptic number.

It is an amenable number.

81211268 is a deficient number, since it is larger than the sum of its proper divisors (60908458).

81211268 is a wasteful number, since it uses less digits than its factorization.

81211268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20302821 (or 20302819 counting only the distinct ones).

The product of its digits is 1536, while the sum is 29.

The square root of 81211268 is about 9011.7294677548. The cubic root of 81211268 is about 433.0507188125.

The spelling of 81211268 in words is "eighty-one million, two hundred eleven thousand, two hundred sixty-eight".