72820172 has 6 divisors (see below), whose sum is σ = 127435308. Its totient is φ = 36410084.

The previous prime is 72820157. The next prime is 72820207. The reversal of 72820172 is 27102827.

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 as a sum of consecutive naturals, namely, 9102518 + ... + 9102525.

It is an arithmetic number, because the mean of its divisors is an integer number (21239218).

Almost surely, 2^72820172 is an apocalyptic number.

It is an amenable number.

72820172 is a deficient number, since it is larger than the sum of its proper divisors (54615136).

72820172 is a wasteful number, since it uses less digits than its factorization.

72820172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18205047 (or 18205045 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 72820172 is about 8533.4736186385. The cubic root of 72820172 is about 417.5904583655.

Adding to 72820172 its reverse (27102827), we get a palindrome (99922999).

The spelling of 72820172 in words is "seventy-two million, eight hundred twenty thousand, one hundred seventy-two".