172406491 has 2 divisors, whose sum is σ = 172406492. Its totient is φ = 172406490.

The previous prime is 172406489. The next prime is 172406501. The reversal of 172406491 is 194604271.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 172406491 - 2¹ = 172406489 is a prime.

Together with 172406489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (172406441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86203245 + 86203246.

It is an arithmetic number, because the mean of its divisors is an integer number (86203246).

Almost surely, 2^172406491 is an apocalyptic number.

172406491 is a deficient number, since it is larger than the sum of its proper divisors (1).

172406491 is an equidigital number, since it uses as much as digits as its factorization.

172406491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 172406491 is about 13130.3652272128. The cubic root of 172406491 is about 556.5675361426.

The spelling of 172406491 in words is "one hundred seventy-two million, four hundred six thousand, four hundred ninety-one".