721542542 has 24 divisors (see below), whose sum is σ = 1259948520. Its totient is φ = 309004080.

The previous prime is 721542529. The next prime is 721542557. The reversal of 721542542 is 245245127.

721542542 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 721542499 and 721542508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 246584 + ... + 249492.

It is an arithmetic number, because the mean of its divisors is an integer number (52497855).

Almost surely, 2^721542542 is an apocalyptic number.

721542542 is a deficient number, since it is larger than the sum of its proper divisors (538405978).

721542542 is a wasteful number, since it uses less digits than its factorization.

721542542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5456 (or 5449 counting only the distinct ones).

The product of its digits is 22400, while the sum is 32.

The square root of 721542542 is about 26861.5439243540. The cubic root of 721542542 is about 896.9205626665.

Adding to 721542542 its reverse (245245127), we get a palindrome (966787669).

The spelling of 721542542 in words is "seven hundred twenty-one million, five hundred forty-two thousand, five hundred forty-two".