19873121 has 2 divisors, whose sum is σ = 19873122. Its totient is φ = 19873120.

The previous prime is 19873111. The next prime is 19873141. The reversal of 19873121 is 12137891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12250000 + 7623121 = 3500^2 + 2761^2 .

It is a cyclic number.

It is not a de Polignac number, because 19873121 - 2¹⁴ = 19856737 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19873111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9936560 + 9936561.

It is an arithmetic number, because the mean of its divisors is an integer number (9936561).

Almost surely, 2^19873121 is an apocalyptic number.

It is an amenable number.

19873121 is a deficient number, since it is larger than the sum of its proper divisors (1).

19873121 is an equidigital number, since it uses as much as digits as its factorization.

19873121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 32.

The square root of 19873121 is about 4457.9278818752. The cubic root of 19873121 is about 270.8665392238.

The spelling of 19873121 in words is "nineteen million, eight hundred seventy-three thousand, one hundred twenty-one".