172778423 has 2 divisors, whose sum is σ = 172778424. Its totient is φ = 172778422.

The previous prime is 172778399. The next prime is 172778453. The reversal of 172778423 is 324877271.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172778423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172778453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86389211 + 86389212.

It is an arithmetic number, because the mean of its divisors is an integer number (86389212).

Almost surely, 2^172778423 is an apocalyptic number.

172778423 is a deficient number, since it is larger than the sum of its proper divisors (1).

172778423 is an equidigital number, since it uses as much as digits as its factorization.

172778423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 131712, while the sum is 41.

The square root of 172778423 is about 13144.5206455009. The cubic root of 172778423 is about 556.9674758365.

The spelling of 172778423 in words is "one hundred seventy-two million, seven hundred seventy-eight thousand, four hundred twenty-three".