72097220 has 24 divisors (see below), whose sum is σ = 163051224. Its totient is φ = 26620416.

The previous prime is 72097213. The next prime is 72097247. The reversal of 72097220 is 2279027.

It can be written as a sum of positive squares in 4 ways, for example, as 51076 + 72046144 = 226^2 + 8488^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138389 + ... + 138908.

It is an arithmetic number, because the mean of its divisors is an integer number (6793801).

Almost surely, 2^72097220 is an apocalyptic number.

It is an amenable number.

72097220 is an abundant number, since it is smaller than the sum of its proper divisors (90954004).

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

72097220 is a wasteful number, since it uses less digits than its factorization.

72097220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277319 (or 277317 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 72097220 is about 8491.0081851333. The cubic root of 72097220 is about 416.2039264596.

The spelling of 72097220 in words is "seventy-two million, ninety-seven thousand, two hundred twenty".