643034731 has 2 divisors, whose sum is σ = 643034732. Its totient is φ = 643034730.

The previous prime is 643034723. The next prime is 643034747. The reversal of 643034731 is 137430346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643034731 - 2³ = 643034723 is a prime.

It is a super-2 number, since 2×643034731² = 826987330544484722, which contains 22 as substring.

It is equal to p_33450178 and since 643034731 and 33450178 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 643034693 and 643034702.

It is not a weakly prime, because it can be changed into another prime (643034761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321517365 + 321517366.

It is an arithmetic number, because the mean of its divisors is an integer number (321517366).

Almost surely, 2^643034731 is an apocalyptic number.

643034731 is a deficient number, since it is larger than the sum of its proper divisors (1).

643034731 is an equidigital number, since it uses as much as digits as its factorization.

643034731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 31.

The square root of 643034731 is about 25358.1294854333. The cubic root of 643034731 is about 863.1338390924.

The spelling of 643034731 in words is "six hundred forty-three million, thirty-four thousand, seven hundred thirty-one".