1923681989 has 2 divisors, whose sum is σ = 1923681990. Its totient is φ = 1923681988.

The previous prime is 1923681979. The next prime is 1923682051. The reversal of 1923681989 is 9891863291.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1236717889 + 686964100 = 35167^2 + 26210^2 .

It is a cyclic number.

It is not a de Polignac number, because 1923681989 - 2²⁸ = 1655246533 is a prime.

It is a super-2 number, since 2×1923681989² = 7401104789605992242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1923681959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 961840994 + 961840995.

It is an arithmetic number, because the mean of its divisors is an integer number (961840995).

Almost surely, 2^1923681989 is an apocalyptic number.

It is an amenable number.

1923681989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1923681989 is an equidigital number, since it uses as much as digits as its factorization.

1923681989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1679616, while the sum is 56.

The square root of 1923681989 is about 43859.7992357466. The cubic root of 1923681989 is about 1243.6869947663.

The spelling of 1923681989 in words is "one billion, nine hundred twenty-three million, six hundred eighty-one thousand, nine hundred eighty-nine".