72320805 has 72 divisors (see below), whose sum is σ = 136779552. Its totient is φ = 35329536.

The previous prime is 72320789. The next prime is 72320819. The reversal of 72320805 is 50802327.

It is not a de Polignac number, because 72320805 - 2⁴ = 72320789 is a prime.

It is a congruent 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 71 ways as a sum of consecutive naturals, for example, 871294 + ... + 871376.

It is an arithmetic number, because the mean of its divisors is an integer number (1899716).

Almost surely, 2^72320805 is an apocalyptic number.

It is an amenable number.

72320805 is a deficient number, since it is larger than the sum of its proper divisors (64458747).

72320805 is a wasteful number, since it uses less digits than its factorization.

72320805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 72320805 is about 8504.1639800747. The cubic root of 72320805 is about 416.6337207728.

It can be divided in two parts, 723 and 20805, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 72320805 in words is "seventy-two million, three hundred twenty thousand, eight hundred five".