721237940 has 48 divisors (see below), whose sum is σ = 1572340224. Its totient is φ = 277603200.

The previous prime is 721237931. The next prime is 721237949. The reversal of 721237940 is 49732127.

It is an interprime number because it is at equal distance from previous prime (721237931) and next prime (721237949).

It is a self number, because there is not a number n which added to its sum of digits gives 721237940.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721237949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109007 + ... + 115433.

It is an arithmetic number, because the mean of its divisors is an integer number (32757088).

Almost surely, 2^721237940 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 721237940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (786170112).

721237940 is an abundant number, since it is smaller than the sum of its proper divisors (851102284).

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

721237940 is a wasteful number, since it uses less digits than its factorization.

721237940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6648 (or 6646 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 721237940 is about 26855.8734730412. The cubic root of 721237940 is about 896.7943320633.

The spelling of 721237940 in words is "seven hundred twenty-one million, two hundred thirty-seven thousand, nine hundred forty".