1931681669 has 2 divisors, whose sum is σ = 1931681670. Its totient is φ = 1931681668.

The previous prime is 1931681663. The next prime is 1931681671. The reversal of 1931681669 is 9661861391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1567368100 + 364313569 = 39590^2 + 19087^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1931681669 is a prime.

It is a super-2 number, since 2×1931681669² = 7462788140701251122, which contains 22 as substring.

Together with 1931681671, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1931681663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 965840834 + 965840835.

It is an arithmetic number, because the mean of its divisors is an integer number (965840835).

Almost surely, 2^1931681669 is an apocalyptic number.

It is an amenable number.

1931681669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1931681669 is an equidigital number, since it uses as much as digits as its factorization.

1931681669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 419904, while the sum is 50.

The square root of 1931681669 is about 43950.9006619887. The cubic root of 1931681669 is about 1245.4085784476.

The spelling of 1931681669 in words is "one billion, nine hundred thirty-one million, six hundred eighty-one thousand, six hundred sixty-nine".