81280870 has 16 divisors (see below), whose sum is σ = 159606288. Its totient is φ = 29556640.

The previous prime is 81280811. The next prime is 81280891. The reversal of 81280870 is 7808218.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 369349 + ... + 369568.

It is an arithmetic number, because the mean of its divisors is an integer number (9975393).

Almost surely, 2^81280870 is an apocalyptic number.

81280870 is a deficient number, since it is larger than the sum of its proper divisors (78325418).

81280870 is a wasteful number, since it uses less digits than its factorization.

81280870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738935.

The product of its (nonzero) digits is 7168, while the sum is 34.

The square root of 81280870 is about 9015.5903855488. The cubic root of 81280870 is about 433.1743986505.

The spelling of 81280870 in words is "eighty-one million, two hundred eighty thousand, eight hundred seventy".