721124940 has 24 divisors (see below), whose sum is σ = 2019150000. Its totient is φ = 192299968.

The previous prime is 721124909. The next prime is 721124941. The reversal of 721124940 is 49421127.

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 = 721124898 and 721124907.

It is not an unprimeable number, because it can be changed into a prime (721124941) 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 7 ways as a sum of consecutive naturals, for example, 6009315 + ... + 6009434.

It is an arithmetic number, because the mean of its divisors is an integer number (84131250).

Almost surely, 2^721124940 is an apocalyptic number.

It is an amenable number.

721124940 is an abundant number, since it is smaller than the sum of its proper divisors (1298025060).

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

721124940 is a wasteful number, since it uses less digits than its factorization.

721124940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12018761 (or 12018759 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 721124940 is about 26853.7695677907. The cubic root of 721124940 is about 896.7474945141.

The spelling of 721124940 in words is "seven hundred twenty-one million, one hundred twenty-four thousand, nine hundred forty".