642470197 has 2 divisors, whose sum is σ = 642470198. Its totient is φ = 642470196.

The previous prime is 642470177. The next prime is 642470249. The reversal of 642470197 is 791074246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 473106001 + 169364196 = 21751^2 + 13014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642470197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642470167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321235098 + 321235099.

It is an arithmetic number, because the mean of its divisors is an integer number (321235099).

Almost surely, 2^642470197 is an apocalyptic number.

It is an amenable number.

642470197 is a deficient number, since it is larger than the sum of its proper divisors (1).

642470197 is an equidigital number, since it uses as much as digits as its factorization.

642470197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 40.

The square root of 642470197 is about 25346.9958180452. The cubic root of 642470197 is about 862.8811772276.

The spelling of 642470197 in words is "six hundred forty-two million, four hundred seventy thousand, one hundred ninety-seven".