721220442 has 8 divisors (see below), whose sum is σ = 1442440896. Its totient is φ = 240406812.

The previous prime is 721220387. The next prime is 721220447. The reversal of 721220442 is 244022127.

It is a sphenic number, since it is the product of 3 distinct primes.

721220442 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (721220447) 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 3 ways as a sum of consecutive naturals, for example, 60101698 + ... + 60101709.

It is an arithmetic number, because the mean of its divisors is an integer number (180305112).

Almost surely, 2^721220442 is an apocalyptic number.

721220442 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

721220442 is a wasteful number, since it uses less digits than its factorization.

721220442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120203412.

The product of its (nonzero) digits is 1792, while the sum is 24.

The square root of 721220442 is about 26855.5476950294. The cubic root of 721220442 is about 896.7870796096.

Adding to 721220442 its reverse (244022127), we get a palindrome (965242569).

The spelling of 721220442 in words is "seven hundred twenty-one million, two hundred twenty thousand, four hundred forty-two".