19152257821 has 2 divisors, whose sum is σ = 19152257822. Its totient is φ = 19152257820.

The previous prime is 19152257819. The next prime is 19152257827. The reversal of 19152257821 is 12875225191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14953865796 + 4198392025 = 122286^2 + 64795^2 .

It is a cyclic number.

It is not a de Polignac number, because 19152257821 - 2¹ = 19152257819 is a prime.

Together with 19152257819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19152257827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9576128910 + 9576128911.

It is an arithmetic number, because the mean of its divisors is an integer number (9576128911).

Almost surely, 2^19152257821 is an apocalyptic number.

It is an amenable number.

19152257821 is a deficient number, since it is larger than the sum of its proper divisors (1).

19152257821 is an equidigital number, since it uses as much as digits as its factorization.

19152257821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 100800, while the sum is 43.

The spelling of 19152257821 in words is "nineteen billion, one hundred fifty-two million, two hundred fifty-seven thousand, eight hundred twenty-one".