721003280 has 40 divisors (see below), whose sum is σ = 1691188632. Its totient is φ = 285845504.

The previous prime is 721003271. The next prime is 721003289. The reversal of 721003280 is 82300127.

It is an interprime number because it is at equal distance from previous prime (721003271) and next prime (721003289).

It can be written as a sum of positive squares in 4 ways, for example, as 4477456 + 716525824 = 2116^2 + 26768^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (721003289) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30839 + ... + 48918.

Almost surely, 2^721003280 is an apocalyptic number.

It is an amenable number.

721003280 is an abundant number, since it is smaller than the sum of its proper divisors (970185352).

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

721003280 is a wasteful number, since it uses less digits than its factorization.

721003280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79883 (or 79877 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 721003280 is about 26851.5042409173. The cubic root of 721003280 is about 896.6970619978.

The spelling of 721003280 in words is "seven hundred twenty-one million, three thousand, two hundred eighty".