721000 has 64 divisors (see below), whose sum is σ = 1946880. Its totient is φ = 244800.

The previous prime is 720997. The next prime is 721003. The reversal of 721000 is 127.

It is an interprime number because it is at equal distance from previous prime (720997) and next prime (721003).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6949 + ... + 7051.

It is an arithmetic number, because the mean of its divisors is an integer number (30420).

2⁷²¹⁰⁰⁰ is an apocalyptic number.

721000 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 721000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (973440).

721000 is an abundant number, since it is smaller than the sum of its proper divisors (1225880).

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

721000 is a wasteful number, since it uses less digits than its factorization.

721000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 14, while the sum is 10.

The square root of 721000 is about 849.1171886142. The cubic root of 721000 is about 89.6695702239.

Adding to 721000 its reverse (127), we get a palindrome (721127).

The spelling of 721000 in words is "seven hundred twenty-one thousand", and thus it is an iban number.