1944311381 has 2 divisors, whose sum is σ = 1944311382. Its totient is φ = 1944311380.

The previous prime is 1944311339. The next prime is 1944311407. The reversal of 1944311381 is 1831134491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1706103025 + 238208356 = 41305^2 + 15434^2 .

It is a cyclic number.

It is not a de Polignac number, because 1944311381 - 2²⁶ = 1877202517 is a prime.

It is a super-2 number, since 2×1944311381² = 7560693492572254322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1944341381) 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, 972155690 + 972155691.

It is an arithmetic number, because the mean of its divisors is an integer number (972155691).

Almost surely, 2^1944311381 is an apocalyptic number.

It is an amenable number.

1944311381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1944311381 is an equidigital number, since it uses as much as digits as its factorization.

1944311381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 35.

The square root of 1944311381 is about 44094.3463609565. The cubic root of 1944311381 is about 1248.1169259301.

The spelling of 1944311381 in words is "one billion, nine hundred forty-four million, three hundred eleven thousand, three hundred eighty-one".