71691820 has 24 divisors (see below), whose sum is σ = 152047728. Its totient is φ = 28392000.

The previous prime is 71691791. The next prime is 71691877. The reversal of 71691820 is 2819617.

It is a happy number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 15726 + ... + 19765.

It is an arithmetic number, because the mean of its divisors is an integer number (6335322).

Almost surely, 2^71691820 is an apocalyptic number.

It is an amenable number.

71691820 is an abundant number, since it is smaller than the sum of its proper divisors (80355908).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71691820 is a wasteful number, since it uses less digits than its factorization.

71691820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35601 (or 35599 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 71691820 is about 8467.1022197680. The cubic root of 71691820 is about 415.4223599587.

The spelling of 71691820 in words is "seventy-one million, six hundred ninety-one thousand, eight hundred twenty".