1949219981 has 2 divisors, whose sum is σ = 1949219982. Its totient is φ = 1949219980.

The previous prime is 1949219969. The next prime is 1949220071. The reversal of 1949219981 is 1899129491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1948427881 + 792100 = 44141^2 + 890^2 .

It is a cyclic number.

It is not a de Polignac number, because 1949219981 - 2⁶ = 1949219917 is a prime.

It is a super-2 number, since 2×1949219981² = 7598917068659280722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1949219381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 974609990 + 974609991.

It is an arithmetic number, because the mean of its divisors is an integer number (974609991).

Almost surely, 2^1949219981 is an apocalyptic number.

It is an amenable number.

1949219981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1949219981 is an equidigital number, since it uses as much as digits as its factorization.

1949219981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 53.

The square root of 1949219981 is about 44149.9714722445. The cubic root of 1949219981 is about 1249.1663734570.

The spelling of 1949219981 in words is "one billion, nine hundred forty-nine million, two hundred nineteen thousand, nine hundred eighty-one".