72155520 has 96 divisors (see below), whose sum is σ = 249181920. Its totient is φ = 19239936.

The previous prime is 72155491. The next prime is 72155537. The reversal of 72155520 is 2555127.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 504 + ... + 12023.

It is an arithmetic number, because the mean of its divisors is an integer number (2595645).

Almost surely, 2^72155520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72155520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124590960).

72155520 is an abundant number, since it is smaller than the sum of its proper divisors (177026400).

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

72155520 is a wasteful number, since it uses less digits than its factorization.

72155520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12552 (or 12537 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 27.

The square root of 72155520 is about 8494.4405348440. The cubic root of 72155520 is about 416.3160812762.

The spelling of 72155520 in words is "seventy-two million, one hundred fifty-five thousand, five hundred twenty".