81577811 has 8 divisors (see below), whose sum is σ = 98138880. Its totient is φ = 66243528.

The previous prime is 81577807. The next prime is 81577813. The reversal of 81577811 is 11877518.

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

It is a cyclic number.

It is not a de Polignac number, because 81577811 - 2² = 81577807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81577813) 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, 306551 + ... + 306816.

It is an arithmetic number, because the mean of its divisors is an integer number (12267360).

Almost surely, 2^81577811 is an apocalyptic number.

81577811 is a deficient number, since it is larger than the sum of its proper divisors (16561069).

81577811 is a wasteful number, since it uses less digits than its factorization.

81577811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 613393.

The product of its digits is 15680, while the sum is 38.

The square root of 81577811 is about 9032.0435672111. The cubic root of 81577811 is about 433.7012586589.

The spelling of 81577811 in words is "eighty-one million, five hundred seventy-seven thousand, eight hundred eleven".