646885621264 has 15 divisors (see below), whose sum is σ = 1253347124493. Its totient is φ = 323441202048.

The previous prime is 646885621259. The next prime is 646885621289. The reversal of 646885621264 is 462126588646.

It is a happy number.

The square root of 646885621264 is 804292.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 306539395600 + 340346225664 = 553660^2 + 583392^2 .

It is a super-2 number, since 2×646885621264² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646885621199 and 646885621208.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 3116632 + ... + 3317704.

Almost surely, 2^646885621264 is an apocalyptic number.

646885621264 is the 804292-nd square number.

It is an amenable number.

646885621264 is a deficient number, since it is larger than the sum of its proper divisors (606461503229).

646885621264 is an frugal number, since it uses more digits than its factorization.

646885621264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402154 (or 201075 counting only the distinct ones).

The product of its digits is 26542080, while the sum is 58.

The spelling of 646885621264 in words is "six hundred forty-six billion, eight hundred eighty-five million, six hundred twenty-one thousand, two hundred sixty-four".