721998109000 has 256 divisors, whose sum is σ = 2059162560000. Its totient is φ = 231299481600.

The previous prime is 721998108989. The next prime is 721998109003. The reversal of 721998109000 is 901899127.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (721998109003) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 16519176 + ... + 16562824.

It is an arithmetic number, because the mean of its divisors is an integer number (8043603750).

Almost surely, 2^721998109000 is an apocalyptic number.

721998109000 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 721998109000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1029581280000).

721998109000 is an abundant number, since it is smaller than the sum of its proper divisors (1337164451000).

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

721998109000 is a wasteful number, since it uses less digits than its factorization.

721998109000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43833 (or 43819 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 46.

The spelling of 721998109000 in words is "seven hundred twenty-one billion, nine hundred ninety-eight million, one hundred nine thousand".