1971712489 has 2 divisors, whose sum is σ = 1971712490. Its totient is φ = 1971712488.

The previous prime is 1971712487. The next prime is 1971712531. The reversal of 1971712489 is 9842171791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1734306025 + 237406464 = 41645^2 + 15408^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971712489 - 2¹ = 1971712487 is a prime.

Together with 1971712487, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1971712487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985856244 + 985856245.

It is an arithmetic number, because the mean of its divisors is an integer number (985856245).

Almost surely, 2^1971712489 is an apocalyptic number.

It is an amenable number.

1971712489 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971712489 is an equidigital number, since it uses as much as digits as its factorization.

1971712489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 49.

The square root of 1971712489 is about 44403.9692932963. The cubic root of 1971712489 is about 1253.9528179947.

The spelling of 1971712489 in words is "one billion, nine hundred seventy-one million, seven hundred twelve thousand, four hundred eighty-nine".