646129441 has 4 divisors (see below), whose sum is σ = 655773232. Its totient is φ = 636485652.

The previous prime is 646129439. The next prime is 646129457. The reversal of 646129441 is 144921646.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 646129441 - 2¹ = 646129439 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 646129441.

It is not an unprimeable number, because it can be changed into a prime (646129241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4821795 + ... + 4821928.

It is an arithmetic number, because the mean of its divisors is an integer number (163943308).

Almost surely, 2^646129441 is an apocalyptic number.

It is an amenable number.

646129441 is a deficient number, since it is larger than the sum of its proper divisors (9643791).

646129441 is an equidigital number, since it uses as much as digits as its factorization.

646129441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9643790.

The product of its digits is 41472, while the sum is 37.

The square root of 646129441 is about 25419.0763207478. The cubic root of 646129441 is about 864.5162813884.

The spelling of 646129441 in words is "six hundred forty-six million, one hundred twenty-nine thousand, four hundred forty-one".