2131821389 has 2 divisors, whose sum is σ = 2131821390. Its totient is φ = 2131821388.

The previous prime is 2131821383. The next prime is 2131821431. The reversal of 2131821389 is 9831281312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1932305764 + 199515625 = 43958^2 + 14125^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131821389 - 2¹² = 2131817293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2131821383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065910694 + 1065910695.

It is an arithmetic number, because the mean of its divisors is an integer number (1065910695).

Almost surely, 2^2131821389 is an apocalyptic number.

It is an amenable number.

2131821389 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131821389 is an equidigital number, since it uses as much as digits as its factorization.

2131821389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 38.

The square root of 2131821389 is about 46171.6513566496. The cubic root of 2131821389 is about 1287.0149896415.

The spelling of 2131821389 in words is "two billion, one hundred thirty-one million, eight hundred twenty-one thousand, three hundred eighty-nine".