646424442240 has 64 divisors (see below), whose sum is σ = 2060477915760. Its totient is φ = 172379850752.

The previous prime is 646424442187. The next prime is 646424442241. The reversal of 646424442240 is 42244424646.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 646424442192 and 646424442201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646424442241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168337779 + ... + 168341618.

Almost surely, 2^646424442240 is an apocalyptic number.

646424442240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646424442240 is an abundant number, since it is smaller than the sum of its proper divisors (1414053473520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646424442240 is a wasteful number, since it uses less digits than its factorization.

646424442240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336679419 (or 336679407 counting only the distinct ones).

The product of its (nonzero) digits is 1179648, while the sum is 42.

Adding to 646424442240 its reverse (42244424646), we get a palindrome (688668866886).

The spelling of 646424442240 in words is "six hundred forty-six billion, four hundred twenty-four million, four hundred forty-two thousand, two hundred forty".