71820945 has 32 divisors (see below), whose sum is σ = 145923840. Its totient is φ = 32832000.

The previous prime is 71820923. The next prime is 71820961. The reversal of 71820945 is 54902817.

It is not a de Polignac number, because 71820945 - 2¹⁸ = 71558801 is a prime.

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 31 ways as a sum of consecutive naturals, for example, 37056 + ... + 38945.

It is an arithmetic number, because the mean of its divisors is an integer number (4560120).

Almost surely, 2^71820945 is an apocalyptic number.

It is an amenable number.

71820945 is an abundant number, since it is smaller than the sum of its proper divisors (74102895).

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

71820945 is a wasteful number, since it uses less digits than its factorization.

71820945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76022 (or 76016 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 71820945 is about 8474.7238893075. The cubic root of 71820945 is about 415.6716177759.

The spelling of 71820945 in words is "seventy-one million, eight hundred twenty thousand, nine hundred forty-five".