1321758197 has 2 divisors, whose sum is σ = 1321758198. Its totient is φ = 1321758196.

The previous prime is 1321758169. The next prime is 1321758239. The reversal of 1321758197 is 7918571231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1139130001 + 182628196 = 33751^2 + 13514^2 .

It is an emirp because it is prime and its reverse (7918571231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1321758197 - 2¹² = 1321754101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321758157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660879098 + 660879099.

It is an arithmetic number, because the mean of its divisors is an integer number (660879099).

Almost surely, 2^1321758197 is an apocalyptic number.

It is an amenable number.

1321758197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321758197 is an equidigital number, since it uses as much as digits as its factorization.

1321758197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 105840, while the sum is 44.

The square root of 1321758197 is about 36355.9925871926. The cubic root of 1321758197 is about 1097.4481333168.

The spelling of 1321758197 in words is "one billion, three hundred twenty-one million, seven hundred fifty-eight thousand, one hundred ninety-seven".