643532651552 has 384 divisors, whose sum is σ = 1645083095040. Its totient is φ = 241367777280.

The previous prime is 643532651497. The next prime is 643532651609. The reversal of 643532651552 is 255156235346.

It is a super-2 number, since 2×643532651552² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643532651497 and 643532651506.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1085214968 + ... + 1085215560.

It is an arithmetic number, because the mean of its divisors is an integer number (4284070560).

Almost surely, 2^643532651552 is an apocalyptic number.

643532651552 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643532651552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (822541547520).

643532651552 is an abundant number, since it is smaller than the sum of its proper divisors (1001550443488).

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

643532651552 is a wasteful number, since it uses less digits than its factorization.

643532651552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004 (or 996 counting only the distinct ones).

The product of its digits is 3240000, while the sum is 47.

Adding to 643532651552 its reverse (255156235346), we get a palindrome (898688886898).

The spelling of 643532651552 in words is "six hundred forty-three billion, five hundred thirty-two million, six hundred fifty-one thousand, five hundred fifty-two".