1968991231 has 2 divisors, whose sum is σ = 1968991232. Its totient is φ = 1968991230.

The previous prime is 1968991207. The next prime is 1968991249. The reversal of 1968991231 is 1321998691.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1968991231 - 2⁷ = 1968991103 is a prime.

It is a super-2 number, since 2×1968991231² = 7753852935509790722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1968991201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 984495615 + 984495616.

It is an arithmetic number, because the mean of its divisors is an integer number (984495616).

Almost surely, 2^1968991231 is an apocalyptic number.

1968991231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1968991231 is an equidigital number, since it uses as much as digits as its factorization.

1968991231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 49.

The square root of 1968991231 is about 44373.3166553955. The cubic root of 1968991231 is about 1253.3756716134.

The spelling of 1968991231 in words is "one billion, nine hundred sixty-eight million, nine hundred ninety-one thousand, two hundred thirty-one".