643250197 has 2 divisors, whose sum is σ = 643250198. Its totient is φ = 643250196.

The previous prime is 643250191. The next prime is 643250203. The reversal of 643250197 is 791052346.

It is a balanced prime because it is at equal distance from previous prime (643250191) and next prime (643250203).

It can be written as a sum of positive squares in only one way, i.e., 603635761 + 39614436 = 24569^2 + 6294^2 .

It is a cyclic number.

It is not a de Polignac number, because 643250197 - 2¹⁵ = 643217429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643250191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321625098 + 321625099.

It is an arithmetic number, because the mean of its divisors is an integer number (321625099).

Almost surely, 2^643250197 is an apocalyptic number.

It is an amenable number.

643250197 is a deficient number, since it is larger than the sum of its proper divisors (1).

643250197 is an equidigital number, since it uses as much as digits as its factorization.

643250197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 643250197 is about 25362.3775896504. The cubic root of 643250197 is about 863.2302336927.

The spelling of 643250197 in words is "six hundred forty-three million, two hundred fifty thousand, one hundred ninety-seven".