646549601629 has 2 divisors, whose sum is σ = 646549601630. Its totient is φ = 646549601628.

The previous prime is 646549601603. The next prime is 646549601647. The reversal of 646549601629 is 926106945646.

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., 579417828025 + 67131773604 = 761195^2 + 259098^2 .

It is a cyclic number.

It is not a de Polignac number, because 646549601629 - 2¹⁹ = 646549077341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646549601669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323274800814 + 323274800815.

It is an arithmetic number, because the mean of its divisors is an integer number (323274800815).

Almost surely, 2^646549601629 is an apocalyptic number.

It is an amenable number.

646549601629 is a deficient number, since it is larger than the sum of its proper divisors (1).

646549601629 is an equidigital number, since it uses as much as digits as its factorization.

646549601629 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16796160, while the sum is 58.

The spelling of 646549601629 in words is "six hundred forty-six billion, five hundred forty-nine million, six hundred one thousand, six hundred twenty-nine".