729721889820 has 864 divisors, whose sum is σ = 2898678182400. Its totient is φ = 150837603840.

The previous prime is 729721889797. The next prime is 729721889839. The reversal of 729721889820 is 28988127927.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 1107316651 + ... + 1107317309.

It is an arithmetic number, because the mean of its divisors is an integer number (3354951600).

Almost surely, 2^729721889820 is an apocalyptic number.

729721889820 is a gapful number since it is divisible by the number (70) 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 729721889820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1449339091200).

729721889820 is an abundant number, since it is smaller than the sum of its proper divisors (2168956292580).

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

729721889820 is a wasteful number, since it uses less digits than its factorization.

729721889820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 981 (or 956 counting only the distinct ones).

The product of its (nonzero) digits is 16257024, while the sum is 63.

The spelling of 729721889820 in words is "seven hundred twenty-nine billion, seven hundred twenty-one million, eight hundred eighty-nine thousand, eight hundred twenty".