643898027 has 2 divisors, whose sum is σ = 643898028. Its totient is φ = 643898026.

The previous prime is 643897921. The next prime is 643898051. The reversal of 643898027 is 720898346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643898027 - 2²⁶ = 576789163 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643898327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321949013 + 321949014.

It is an arithmetic number, because the mean of its divisors is an integer number (321949014).

Almost surely, 2^643898027 is an apocalyptic number.

643898027 is a deficient number, since it is larger than the sum of its proper divisors (1).

643898027 is an equidigital number, since it uses as much as digits as its factorization.

643898027 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 580608, while the sum is 47.

The square root of 643898027 is about 25375.1458517976. The cubic root of 643898027 is about 863.5199285444.

The spelling of 643898027 in words is "six hundred forty-three million, eight hundred ninety-eight thousand, twenty-seven".