721722160 has 80 divisors (see below), whose sum is σ = 1740960000. Its totient is φ = 277954560.

The previous prime is 721722121. The next prime is 721722179. The reversal of 721722160 is 61227127.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 577216 + ... + 578464.

It is an arithmetic number, because the mean of its divisors is an integer number (21762000).

Almost surely, 2^721722160 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 721722160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (870480000).

721722160 is an abundant number, since it is smaller than the sum of its proper divisors (1019237840).

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

721722160 is a wasteful number, since it uses less digits than its factorization.

721722160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1526 (or 1520 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 721722160 is about 26864.8871205520. The cubic root of 721722160 is about 896.9949817995.

Adding to 721722160 its reverse (61227127), we get a palindrome (782949287).

The spelling of 721722160 in words is "seven hundred twenty-one million, seven hundred twenty-two thousand, one hundred sixty".