1936668581 has 2 divisors, whose sum is σ = 1936668582. Its totient is φ = 1936668580.

The previous prime is 1936668571. The next prime is 1936668583. The reversal of 1936668581 is 1858666391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1921419556 + 15249025 = 43834^2 + 3905^2 .

It is a cyclic number.

It is not a de Polignac number, because 1936668581 - 2²² = 1932474277 is a prime.

It is a super-2 number, since 2×1936668581² = 7501370385265107122, which contains 22 as substring.

Together with 1936668583, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1936668583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 968334290 + 968334291.

It is an arithmetic number, because the mean of its divisors is an integer number (968334291).

Almost surely, 2^1936668581 is an apocalyptic number.

It is an amenable number.

1936668581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1936668581 is an equidigital number, since it uses as much as digits as its factorization.

1936668581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1866240, while the sum is 53.

The square root of 1936668581 is about 44007.5968555430. The cubic root of 1936668581 is about 1246.4793908381.

The spelling of 1936668581 in words is "one billion, nine hundred thirty-six million, six hundred sixty-eight thousand, five hundred eighty-one".