72108257 has 4 divisors (see below), whose sum is σ = 77655060. Its totient is φ = 66561456.

The previous prime is 72108251. The next prime is 72108259. The reversal of 72108257 is 75280127.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4227136 + 67881121 = 2056^2 + 8239^2 .

It is not a de Polignac number, because 72108257 - 2⁴ = 72108241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72108251) 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, 2773382 + ... + 2773407.

It is an arithmetic number, because the mean of its divisors is an integer number (19413765).

Almost surely, 2^72108257 is an apocalyptic number.

It is an amenable number.

72108257 is a deficient number, since it is larger than the sum of its proper divisors (5546803).

72108257 is a wasteful number, since it uses less digits than its factorization.

72108257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5546802.

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 72108257 is about 8491.6580830837. The cubic root of 72108257 is about 416.2251635630.

The spelling of 72108257 in words is "seventy-two million, one hundred eight thousand, two hundred fifty-seven".