642227197 has 2 divisors, whose sum is σ = 642227198. Its totient is φ = 642227196.

The previous prime is 642227171. The next prime is 642227233. The reversal of 642227197 is 791722246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 403648281 + 238578916 = 20091^2 + 15446^2 .

It is a cyclic number.

It is not a de Polignac number, because 642227197 - 2²³ = 633838589 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642224197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321113598 + 321113599.

It is an arithmetic number, because the mean of its divisors is an integer number (321113599).

Almost surely, 2^642227197 is an apocalyptic number.

It is an amenable number.

642227197 is a deficient number, since it is larger than the sum of its proper divisors (1).

642227197 is an equidigital number, since it uses as much as digits as its factorization.

642227197 is an odious number, because the sum of its binary digits is odd.

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

The square root of 642227197 is about 25342.2018972306. The cubic root of 642227197 is about 862.7723749993.

The spelling of 642227197 in words is "six hundred forty-two million, two hundred twenty-seven thousand, one hundred ninety-seven".