81280811 has 2 divisors, whose sum is σ = 81280812. Its totient is φ = 81280810.

The previous prime is 81280807. The next prime is 81280891. The reversal of 81280811 is 11808218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81280811 - 2² = 81280807 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81280891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40640405 + 40640406.

It is an arithmetic number, because the mean of its divisors is an integer number (40640406).

Almost surely, 2^81280811 is an apocalyptic number.

81280811 is a deficient number, since it is larger than the sum of its proper divisors (1).

81280811 is an equidigital number, since it uses as much as digits as its factorization.

81280811 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1024, while the sum is 29.

The square root of 81280811 is about 9015.5871134386. The cubic root of 81280811 is about 433.1742938399.

The spelling of 81280811 in words is "eighty-one million, two hundred eighty thousand, eight hundred eleven".