1957216309 has 2 divisors, whose sum is σ = 1957216310. Its totient is φ = 1957216308.

The previous prime is 1957216249. The next prime is 1957216319. The reversal of 1957216309 is 9036127591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1917564100 + 39652209 = 43790^2 + 6297^2 .

It is a cyclic number.

It is not a de Polignac number, because 1957216309 - 2²⁷ = 1822998581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1957216319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 978608154 + 978608155.

It is an arithmetic number, because the mean of its divisors is an integer number (978608155).

Almost surely, 2^1957216309 is an apocalyptic number.

It is an amenable number.

1957216309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1957216309 is an equidigital number, since it uses as much as digits as its factorization.

1957216309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 102060, while the sum is 43.

The square root of 1957216309 is about 44240.4374865349. The cubic root of 1957216309 is about 1250.8722038535.

The spelling of 1957216309 in words is "one billion, nine hundred fifty-seven million, two hundred sixteen thousand, three hundred nine".