172640813 has 2 divisors, whose sum is σ = 172640814. Its totient is φ = 172640812.

The previous prime is 172640803. The next prime is 172640861. The reversal of 172640813 is 318046271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90973444 + 81667369 = 9538^2 + 9037^2 .

It is an emirp because it is prime and its reverse (318046271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172640813 - 2⁶ = 172640749 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 172640813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172640803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86320406 + 86320407.

It is an arithmetic number, because the mean of its divisors is an integer number (86320407).

Almost surely, 2^172640813 is an apocalyptic number.

It is an amenable number.

172640813 is a deficient number, since it is larger than the sum of its proper divisors (1).

172640813 is an equidigital number, since it uses as much as digits as its factorization.

172640813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 172640813 is about 13139.2851023182. The cubic root of 172640813 is about 556.8195703093.

The spelling of 172640813 in words is "one hundred seventy-two million, six hundred forty thousand, eight hundred thirteen".