72120397 has 4 divisors (see below), whose sum is σ = 72438336. Its totient is φ = 71802460.

The previous prime is 72120383. The next prime is 72120407. The reversal of 72120397 is 79302127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72120397 - 2¹¹ = 72118349 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72120337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158629 + ... + 159082.

It is an arithmetic number, because the mean of its divisors is an integer number (18109584).

Almost surely, 2^72120397 is an apocalyptic number.

It is an amenable number.

72120397 is a deficient number, since it is larger than the sum of its proper divisors (317939).

72120397 is a wasteful number, since it uses less digits than its factorization.

72120397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317938.

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 72120397 is about 8492.3728721718. The cubic root of 72120397 is about 416.2485205273.

The spelling of 72120397 in words is "seventy-two million, one hundred twenty thousand, three hundred ninety-seven".