72171013 has 2 divisors, whose sum is σ = 72171014. Its totient is φ = 72171012.

The previous prime is 72170977. The next prime is 72171017. The reversal of 72171013 is 31017127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39715204 + 32455809 = 6302^2 + 5697^2 .

It is an emirp because it is prime and its reverse (31017127) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72171013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72171017) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36085506 + 36085507.

It is an arithmetic number, because the mean of its divisors is an integer number (36085507).

Almost surely, 2^72171013 is an apocalyptic number.

It is an amenable number.

72171013 is a deficient number, since it is larger than the sum of its proper divisors (1).

72171013 is an equidigital number, since it uses as much as digits as its factorization.

72171013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 294, while the sum is 22.

The square root of 72171013 is about 8495.3524353025. The cubic root of 72171013 is about 416.3458758249.

The spelling of 72171013 in words is "seventy-two million, one hundred seventy-one thousand, thirteen".