83720865 has 32 divisors (see below), whose sum is σ = 137894400. Its totient is φ = 43353344.

The previous prime is 83720849. The next prime is 83720911. The reversal of 83720865 is 56802738.

It is a cyclic number.

It is not a de Polignac number, because 83720865 - 2⁴ = 83720849 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 104647 + ... + 105443.

It is an arithmetic number, because the mean of its divisors is an integer number (4309200).

Almost surely, 2^83720865 is an apocalyptic number.

It is an amenable number.

83720865 is a deficient number, since it is larger than the sum of its proper divisors (54173535).

83720865 is a wasteful number, since it uses less digits than its factorization.

83720865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001.

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 83720865 is about 9149.9106553015. The cubic root of 83720865 is about 437.4662656982.

The spelling of 83720865 in words is "eighty-three million, seven hundred twenty thousand, eight hundred sixty-five".