721404042 has 8 divisors (see below), whose sum is σ = 1442808096. Its totient is φ = 240468012.

The previous prime is 721403983. The next prime is 721404049. The reversal of 721404042 is 240404127.

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

721404042 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 (721404049) 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, 60116998 + ... + 60117009.

It is an arithmetic number, because the mean of its divisors is an integer number (180351012).

Almost surely, 2^721404042 is an apocalyptic number.

721404042 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.

721404042 is a wasteful number, since it uses less digits than its factorization.

721404042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120234012.

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

The square root of 721404042 is about 26858.9657656433. The cubic root of 721404042 is about 896.8631710646.

Adding to 721404042 its reverse (240404127), we get a palindrome (961808169).

The spelling of 721404042 in words is "seven hundred twenty-one million, four hundred four thousand, forty-two".