19072121 has 2 divisors, whose sum is σ = 19072122. Its totient is φ = 19072120.

The previous prime is 19072117. The next prime is 19072139. The reversal of 19072121 is 12127091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10310521 + 8761600 = 3211^2 + 2960^2 .

It is an emirp because it is prime and its reverse (12127091) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19072121 - 2² = 19072117 is a prime.

It is not a weakly prime, because it can be changed into another prime (19072021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9536060 + 9536061.

It is an arithmetic number, because the mean of its divisors is an integer number (9536061).

Almost surely, 2^19072121 is an apocalyptic number.

It is an amenable number.

19072121 is a deficient number, since it is larger than the sum of its proper divisors (1).

19072121 is an equidigital number, since it uses as much as digits as its factorization.

19072121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 23.

The square root of 19072121 is about 4367.1639538721. The cubic root of 19072121 is about 267.1773662880.

The spelling of 19072121 in words is "nineteen million, seventy-two thousand, one hundred twenty-one".