642853481 has 2 divisors, whose sum is σ = 642853482. Its totient is φ = 642853480.

The previous prime is 642853433. The next prime is 642853501. The reversal of 642853481 is 184358246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 642115600 + 737881 = 25340^2 + 859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642853481 is a prime.

It is a super-2 number, since 2×642853481² = 826521196067634722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (642853681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321426740 + 321426741.

It is an arithmetic number, because the mean of its divisors is an integer number (321426741).

Almost surely, 2^642853481 is an apocalyptic number.

It is an amenable number.

642853481 is a deficient number, since it is larger than the sum of its proper divisors (1).

642853481 is an equidigital number, since it uses as much as digits as its factorization.

642853481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 184320, while the sum is 41.

The square root of 642853481 is about 25354.5554289560. Note that the first 3 decimals coincide. The cubic root of 642853481 is about 863.0527352776.

The spelling of 642853481 in words is "six hundred forty-two million, eight hundred fifty-three thousand, four hundred eighty-one".