71820881 has 24 divisors (see below), whose sum is σ = 83426112. Its totient is φ = 61661600.

The previous prime is 71820871. The next prime is 71820901. The reversal of 71820881 is 18802817.

It is a de Polignac number, because none of the positive numbers 2^k-71820881 is a prime.

It is a super-2 number, since 2×71820881² = 10316477895232322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (71820821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 364475 + ... + 364671.

It is an arithmetic number, because the mean of its divisors is an integer number (3476088).

Almost surely, 2^71820881 is an apocalyptic number.

It is an amenable number.

71820881 is a deficient number, since it is larger than the sum of its proper divisors (11605231).

71820881 is a wasteful number, since it uses less digits than its factorization.

71820881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373 (or 362 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 35.

The square root of 71820881 is about 8474.7201133725. The cubic root of 71820881 is about 415.6714943068.

The spelling of 71820881 in words is "seventy-one million, eight hundred twenty thousand, eight hundred eighty-one".