643161049 has 2 divisors, whose sum is σ = 643161050. Its totient is φ = 643161048.

The previous prime is 643161007. The next prime is 643161067. The reversal of 643161049 is 940161346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 444914649 + 198246400 = 21093^2 + 14080^2 .

It is a cyclic number.

It is not a de Polignac number, because 643161049 - 2²⁵ = 609606617 is a prime.

It is a super-2 number, since 2×643161049² = 827312269901560802, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (643141049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321580524 + 321580525.

It is an arithmetic number, because the mean of its divisors is an integer number (321580525).

Almost surely, 2^643161049 is an apocalyptic number.

It is an amenable number.

643161049 is a deficient number, since it is larger than the sum of its proper divisors (1).

643161049 is an equidigital number, since it uses as much as digits as its factorization.

643161049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 643161049 is about 25360.6200436819. The cubic root of 643161049 is about 863.1903535110.

The spelling of 643161049 in words is "six hundred forty-three million, one hundred sixty-one thousand, forty-nine".