721500120 has 192 divisors, whose sum is σ = 2575722240. Its totient is φ = 173702400.

The previous prime is 721500119. The next prime is 721500173. The reversal of 721500120 is 21005127.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 721500093 and 721500102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 660775 + ... + 661865.

It is an arithmetic number, because the mean of its divisors is an integer number (13415220).

Almost surely, 2^721500120 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 721500120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1287861120).

721500120 is an abundant number, since it is smaller than the sum of its proper divisors (1854222120).

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

721500120 is a wasteful number, since it uses less digits than its factorization.

721500120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1286 (or 1279 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 721500120 is about 26860.7542708689. The cubic root of 721500120 is about 896.9029846270.

Adding to 721500120 its reverse (21005127), we get a palindrome (742505247).

The spelling of 721500120 in words is "seven hundred twenty-one million, five hundred thousand, one hundred twenty".