740721 has 4 divisors (see below), whose sum is σ = 987632. Its totient is φ = 493812.

The previous prime is 740717. The next prime is 740737. The reversal of 740721 is 127047.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127047 = 3 ⋅42349.

It is not a de Polignac number, because 740721 - 2² = 740717 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (740711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123451 + ... + 123456.

It is an arithmetic number, because the mean of its divisors is an integer number (246908).

2⁷⁴⁰⁷²¹ is an apocalyptic number.

It is an amenable number.

740721 is a deficient number, since it is larger than the sum of its proper divisors (246911).

740721 is a wasteful number, since it uses less digits than its factorization.

740721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246910.

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 740721 is about 860.6514974134. The cubic root of 740721 is about 90.4797834435.

Adding to 740721 its reverse (127047), we get a palindrome (867768).

The spelling of 740721 in words is "seven hundred forty thousand, seven hundred twenty-one", and thus it is an iban number.