172421771 has 2 divisors, whose sum is σ = 172421772. Its totient is φ = 172421770.

The previous prime is 172421749. The next prime is 172421779. The reversal of 172421771 is 177124271.

172421771 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (177124271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172421771 - 2⁶ = 172421707 is a prime.

It is a super-2 number, since 2×172421771² = 59458534229552882, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (172421779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86210885 + 86210886.

It is an arithmetic number, because the mean of its divisors is an integer number (86210886).

Almost surely, 2^172421771 is an apocalyptic number.

172421771 is a deficient number, since it is larger than the sum of its proper divisors (1).

172421771 is an equidigital number, since it uses as much as digits as its factorization.

172421771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5488, while the sum is 32.

The square root of 172421771 is about 13130.9470717081. The cubic root of 172421771 is about 556.5839781004.

The spelling of 172421771 in words is "one hundred seventy-two million, four hundred twenty-one thousand, seven hundred seventy-one".