81280885 has 16 divisors (see below), whose sum is σ = 111960576. Its totient is φ = 55490688.

The previous prime is 81280811. The next prime is 81280891. The reversal of 81280885 is 58808218.

It is a cyclic number.

It is not a de Polignac number, because 81280885 - 2⁹ = 81280373 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3172 + ... + 13138.

It is an arithmetic number, because the mean of its divisors is an integer number (6997536).

Almost surely, 2^81280885 is an apocalyptic number.

It is an amenable number.

81280885 is a deficient number, since it is larger than the sum of its proper divisors (30679691).

81280885 is a wasteful number, since it uses less digits than its factorization.

81280885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10212.

The product of its (nonzero) digits is 40960, while the sum is 40.

The square root of 81280885 is about 9015.5912174410. The cubic root of 81280885 is about 433.1744252973.

The spelling of 81280885 in words is "eighty-one million, two hundred eighty thousand, eight hundred eighty-five".