1801128949 has 2 divisors, whose sum is σ = 1801128950. Its totient is φ = 1801128948.

The previous prime is 1801128943. The next prime is 1801128977. The reversal of 1801128949 is 9498211081.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1476480625 + 324648324 = 38425^2 + 18018^2 .

It is a cyclic number.

It is not a de Polignac number, because 1801128949 - 2⁹ = 1801128437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1801128943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 900564474 + 900564475.

It is an arithmetic number, because the mean of its divisors is an integer number (900564475).

Almost surely, 2^1801128949 is an apocalyptic number.

It is an amenable number.

1801128949 is a deficient number, since it is larger than the sum of its proper divisors (1).

1801128949 is an equidigital number, since it uses as much as digits as its factorization.

1801128949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 43.

The square root of 1801128949 is about 42439.7095772344. The cubic root of 1801128949 is about 1216.6946606265.

The spelling of 1801128949 in words is "one billion, eight hundred one million, one hundred twenty-eight thousand, nine hundred forty-nine".