721294240 has 24 divisors (see below), whose sum is σ = 1704058020. Its totient is φ = 288517632.

The previous prime is 721294219. The next prime is 721294247. The reversal of 721294240 is 42492127.

721294240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 671224464 + 50069776 = 25908^2 + 7076^2 .

It is not an unprimeable number, because it can be changed into a prime (721294247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2253885 + ... + 2254204.

Almost surely, 2^721294240 is an apocalyptic number.

It is an amenable number.

721294240 is an abundant number, since it is smaller than the sum of its proper divisors (982763780).

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

721294240 is a wasteful number, since it uses less digits than its factorization.

721294240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4508104 (or 4508096 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 721294240 is about 26856.9216404263. The cubic root of 721294240 is about 896.8176661136.

The spelling of 721294240 in words is "seven hundred twenty-one million, two hundred ninety-four thousand, two hundred forty".