172863391 has 2 divisors, whose sum is σ = 172863392. Its totient is φ = 172863390.

The previous prime is 172863389. The next prime is 172863407. The reversal of 172863391 is 193368271.

It is a weak prime.

It is an emirp because it is prime and its reverse (193368271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172863391 - 2¹ = 172863389 is a prime.

Together with 172863389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172863091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86431695 + 86431696.

It is an arithmetic number, because the mean of its divisors is an integer number (86431696).

Almost surely, 2^172863391 is an apocalyptic number.

172863391 is a deficient number, since it is larger than the sum of its proper divisors (1).

172863391 is an equidigital number, since it uses as much as digits as its factorization.

172863391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 40.

The square root of 172863391 is about 13147.7523174115. The cubic root of 172863391 is about 557.0587616505.

The spelling of 172863391 in words is "one hundred seventy-two million, eight hundred sixty-three thousand, three hundred ninety-one".