1939491569 has 2 divisors, whose sum is σ = 1939491570. Its totient is φ = 1939491568.

The previous prime is 1939491517. The next prime is 1939491571. The reversal of 1939491569 is 9651949391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1046199025 + 893292544 = 32345^2 + 29888^2 .

It is a cyclic number.

It is not a de Polignac number, because 1939491569 - 2²⁸ = 1671056113 is a prime.

It is a super-4 number, since 4×1939491569⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

Together with 1939491571, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1939491599) 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, 969745784 + 969745785.

It is an arithmetic number, because the mean of its divisors is an integer number (969745785).

Almost surely, 2^1939491569 is an apocalyptic number.

It is an amenable number.

1939491569 is a deficient number, since it is larger than the sum of its proper divisors (1).

1939491569 is an equidigital number, since it uses as much as digits as its factorization.

1939491569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2361960, while the sum is 56.

The square root of 1939491569 is about 44039.6590472724. The cubic root of 1939491569 is about 1247.0847410176.

The spelling of 1939491569 in words is "one billion, nine hundred thirty-nine million, four hundred ninety-one thousand, five hundred sixty-nine".