721743240 has 64 divisors (see below), whose sum is σ = 2235087360. Its totient is φ = 186255360.

The previous prime is 721743227. The next prime is 721743247. The reversal of 721743240 is 42347127.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 721743198 and 721743207.

It is not an unprimeable number, because it can be changed into a prime (721743247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93289 + ... + 100728.

It is an arithmetic number, because the mean of its divisors is an integer number (34923240).

Almost surely, 2^721743240 is an apocalyptic number.

It is an amenable number.

721743240 is an abundant number, since it is smaller than the sum of its proper divisors (1513344120).

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

721743240 is a wasteful number, since it uses less digits than its factorization.

721743240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194062 (or 194058 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 30.

The square root of 721743240 is about 26865.2794513662. The cubic root of 721743240 is about 897.0037148324.

The spelling of 721743240 in words is "seven hundred twenty-one million, seven hundred forty-three thousand, two hundred forty".