643441304545524 has 168 divisors, whose sum is σ = 1696847887750400. Its totient is φ = 213389683924032.

The previous prime is 643441304545513. The next prime is 643441304545643. The reversal of 643441304545524 is 425545403144346.

It is a happy number.

643441304545524 is a `hidden beast` number, since 6 + 4 + 3 + 4 + 4 + 1 + 30 + 4 + 54 + 552 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 16646587782 + ... + 16646626434.

Almost surely, 2^{643441304545524} 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 643441304545524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (848423943875200).

643441304545524 is an abundant number, since it is smaller than the sum of its proper divisors (1053406583204876).

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

643441304545524 is a wasteful number, since it uses less digits than its factorization.

643441304545524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67561 (or 67544 counting only the distinct ones).

The product of its (nonzero) digits is 55296000, while the sum is 54.

The spelling of 643441304545524 in words is "six hundred forty-three trillion, four hundred forty-one billion, three hundred four million, five hundred forty-five thousand, five hundred twenty-four".