721742 has 16 divisors (see below), whose sum is σ = 1277952. Its totient is φ = 299160.

The previous prime is 721739. The next prime is 721783. The reversal of 721742 is 247127.

It is a super-3 number, since 3×721742³ = 1127891155033351464, which contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 398 + ... + 1265.

It is an arithmetic number, because the mean of its divisors is an integer number (79872).

2⁷²¹⁷⁴² is an apocalyptic number.

721742 is a deficient number, since it is larger than the sum of its proper divisors (556210).

721742 is a wasteful number, since it uses less digits than its factorization.

721742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1703.

The product of its digits is 784, while the sum is 23.

The square root of 721742 is about 849.5540006380. The cubic root of 721742 is about 89.7003201129.

Adding to 721742 its reverse (247127), we get a palindrome (968869).

The spelling of 721742 in words is "seven hundred twenty-one thousand, seven hundred forty-two", and thus it is an iban number.