2181946769 has 2 divisors, whose sum is σ = 2181946770. Its totient is φ = 2181946768.

The previous prime is 2181946717. The next prime is 2181946777. The reversal of 2181946769 is 9676491812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1257057025 + 924889744 = 35455^2 + 30412^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181946769 - 2²⁴ = 2165169553 is a prime.

It is a super-2 number, since 2×2181946769² = 9521783405499078722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2181946769.

It is not a weakly prime, because it can be changed into another prime (2181946709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090973384 + 1090973385.

It is an arithmetic number, because the mean of its divisors is an integer number (1090973385).

Almost surely, 2^2181946769 is an apocalyptic number.

It is an amenable number.

2181946769 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181946769 is an equidigital number, since it uses as much as digits as its factorization.

2181946769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 53.

The square root of 2181946769 is about 46711.3130729591. The cubic root of 2181946769 is about 1297.0241138760.

The spelling of 2181946769 in words is "two billion, one hundred eighty-one million, nine hundred forty-six thousand, seven hundred sixty-nine".