642533197 has 2 divisors, whose sum is σ = 642533198. Its totient is φ = 642533196.

The previous prime is 642533189. The next prime is 642533201. The reversal of 642533197 is 791335246.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 547840836 + 94692361 = 23406^2 + 9731^2 .

It is a cyclic number.

It is not a de Polignac number, because 642533197 - 2³ = 642533189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642533117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321266598 + 321266599.

It is an arithmetic number, because the mean of its divisors is an integer number (321266599).

Almost surely, 2^642533197 is an apocalyptic number.

It is an amenable number.

642533197 is a deficient number, since it is larger than the sum of its proper divisors (1).

642533197 is an equidigital number, since it uses as much as digits as its factorization.

642533197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 40.

The square root of 642533197 is about 25348.2385384074. The cubic root of 642533197 is about 862.9093807343.

The spelling of 642533197 in words is "six hundred forty-two million, five hundred thirty-three thousand, one hundred ninety-seven".