172096781 has 2 divisors, whose sum is σ = 172096782. Its totient is φ = 172096780.

The previous prime is 172096753. The next prime is 172096783. The reversal of 172096781 is 187690271.

172096781 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 can be written as a sum of positive squares in only one way, i.e., 171374281 + 722500 = 13091^2 + 850^2 .

It is a cyclic number.

It is not a de Polignac number, because 172096781 - 2²² = 167902477 is a prime.

It is a super-2 number, since 2×172096781² = 59234604061123922, which contains 22 as substring.

Together with 172096783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172096783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86048390 + 86048391.

It is an arithmetic number, because the mean of its divisors is an integer number (86048391).

Almost surely, 2^172096781 is an apocalyptic number.

It is an amenable number.

172096781 is a deficient number, since it is larger than the sum of its proper divisors (1).

172096781 is an equidigital number, since it uses as much as digits as its factorization.

172096781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 41.

The square root of 172096781 is about 13118.5662707477. The cubic root of 172096781 is about 556.2340648383.

The spelling of 172096781 in words is "one hundred seventy-two million, ninety-six thousand, seven hundred eighty-one".