19648895821 has 2 divisors, whose sum is σ = 19648895822. Its totient is φ = 19648895820.

The previous prime is 19648895803. The next prime is 19648895839. The reversal of 19648895821 is 12859884691.

It is a balanced prime because it is at equal distance from previous prime (19648895803) and next prime (19648895839).

It can be written as a sum of positive squares in only one way, i.e., 15268309225 + 4380586596 = 123565^2 + 66186^2 .

It is a cyclic number.

It is not a de Polignac number, because 19648895821 - 2²³ = 19640507213 is a prime.

It is a super-2 number, since 2×19648895821² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19648895821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19648895891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9824447910 + 9824447911.

It is an arithmetic number, because the mean of its divisors is an integer number (9824447911).

Almost surely, 2^19648895821 is an apocalyptic number.

It is an amenable number.

19648895821 is a deficient number, since it is larger than the sum of its proper divisors (1).

19648895821 is an equidigital number, since it uses as much as digits as its factorization.

19648895821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9953280, while the sum is 61.

The spelling of 19648895821 in words is "nineteen billion, six hundred forty-eight million, eight hundred ninety-five thousand, eight hundred twenty-one".