19894274909 has 2 divisors, whose sum is σ = 19894274910. Its totient is φ = 19894274908.

The previous prime is 19894274903. The next prime is 19894274923. The reversal of 19894274909 is 90947249891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18146784100 + 1747490809 = 134710^2 + 41803^2 .

It is a cyclic number.

It is not a de Polignac number, because 19894274909 - 2¹² = 19894270813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19894274903) 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, 9947137454 + 9947137455.

It is an arithmetic number, because the mean of its divisors is an integer number (9947137455).

Almost surely, 2^19894274909 is an apocalyptic number.

It is an amenable number.

19894274909 is a deficient number, since it is larger than the sum of its proper divisors (1).

19894274909 is an equidigital number, since it uses as much as digits as its factorization.

19894274909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11757312, while the sum is 62.

The spelling of 19894274909 in words is "nineteen billion, eight hundred ninety-four million, two hundred seventy-four thousand, nine hundred nine".