646465536 has 168 divisors, whose sum is σ = 1942512390. Its totient is φ = 214990848.

The previous prime is 646465529. The next prime is 646465541. The reversal of 646465536 is 635564646.

It can be written as a sum of positive squares in only one way, i.e., 627803136 + 18662400 = 25056^2 + 4320^2 .

It is a junction number, because it is equal to n+sod(n) for n = 646465491 and 646465500.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 1492776 + ... + 1493208.

Almost surely, 2^646465536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646465536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (971256195).

646465536 is an abundant number, since it is smaller than the sum of its proper divisors (1296046854).

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

646465536 is an frugal number, since it uses more digits than its factorization.

646465536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473 (or 438 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 45.

The square root of 646465536 is about 25425.6865394034. The cubic root of 646465536 is about 864.6661529239. Note that the first 3 decimals are identical.

The spelling of 646465536 in words is "six hundred forty-six million, four hundred sixty-five thousand, five hundred thirty-six".