19172081 has 2 divisors, whose sum is σ = 19172082. Its totient is φ = 19172080.

The previous prime is 19172071. The next prime is 19172089. The reversal of 19172081 is 18027191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11560000 + 7612081 = 3400^2 + 2759^2 .

It is a cyclic number.

It is not a de Polignac number, because 19172081 - 2¹⁸ = 18909937 is a prime.

It is a super-2 number, since 2×19172081² = 735137379741122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19172089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9586040 + 9586041.

It is an arithmetic number, because the mean of its divisors is an integer number (9586041).

Almost surely, 2^19172081 is an apocalyptic number.

It is an amenable number.

19172081 is a deficient number, since it is larger than the sum of its proper divisors (1).

19172081 is an equidigital number, since it uses as much as digits as its factorization.

19172081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 19172081 is about 4378.5934956330. The cubic root of 19172081 is about 267.6433261096.

The spelling of 19172081 in words is "nineteen million, one hundred seventy-two thousand, eighty-one".