646404434 has 48 divisors (see below), whose sum is σ = 1121100120. Its totient is φ = 277758720.

The previous prime is 646404433. The next prime is 646404449. The reversal of 646404434 is 434404646.

It can be written as a sum of positive squares in 4 ways, for example, as 115240225 + 531164209 = 10735^2 + 23047^2 .

It is a junction number, because it is equal to n+sod(n) for n = 646404394 and 646404403.

It is not an unprimeable number, because it can be changed into a prime (646404431) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 571982 + ... + 573110.

Almost surely, 2^646404434 is an apocalyptic number.

646404434 is a deficient number, since it is larger than the sum of its proper divisors (474695686).

646404434 is a wasteful number, since it uses less digits than its factorization.

646404434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1243 (or 1224 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 35.

The square root of 646404434 is about 25424.4849308693. The cubic root of 646404434 is about 864.6389101744.

The spelling of 646404434 in words is "six hundred forty-six million, four hundred four thousand, four hundred thirty-four".