19911473 has 2 divisors, whose sum is σ = 19911474. Its totient is φ = 19911472.

The previous prime is 19911469. The next prime is 19911509. The reversal of 19911473 is 37411991.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17405584 + 2505889 = 4172^2 + 1583^2 .

It is an emirp because it is prime and its reverse (37411991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19911473 - 2² = 19911469 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (19911413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9955736 + 9955737.

It is an arithmetic number, because the mean of its divisors is an integer number (9955737).

Almost surely, 2^19911473 is an apocalyptic number.

It is an amenable number.

19911473 is a deficient number, since it is larger than the sum of its proper divisors (1).

19911473 is an equidigital number, since it uses as much as digits as its factorization.

19911473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6804, while the sum is 35.

The square root of 19911473 is about 4462.2273586181. The cubic root of 19911473 is about 271.0406705390.

The spelling of 19911473 in words is "nineteen million, nine hundred eleven thousand, four hundred seventy-three".