643919492400 has 480 divisors, whose sum is σ = 2312064518400. Its totient is φ = 152233574400.

The previous prime is 643919492353. The next prime is 643919492459. The reversal of 643919492400 is 4294919346.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 69375760 + ... + 69385040.

It is an arithmetic number, because the mean of its divisors is an integer number (4816801080).

Almost surely, 2^643919492400 is an apocalyptic number.

643919492400 is a gapful number since it is divisible by the number (60) 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 643919492400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1156032259200).

643919492400 is an abundant number, since it is smaller than the sum of its proper divisors (1668145026000).

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

643919492400 is a wasteful number, since it uses less digits than its factorization.

643919492400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9517 (or 9506 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 51.

The spelling of 643919492400 in words is "six hundred forty-three billion, nine hundred nineteen million, four hundred ninety-two thousand, four hundred".