740021 has 2 divisors, whose sum is σ = 740022. Its totient is φ = 740020.

The previous prime is 740011. The next prime is 740023. The reversal of 740021 is 120047.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 703921 + 36100 = 839^2 + 190^2 .

It is an emirp because it is prime and its reverse (120047) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 740021 - 2⁶ = 739957 is a prime.

Together with 740023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 739978 and 740005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (740023) 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 as a sum of consecutive naturals, namely, 370010 + 370011.

It is an arithmetic number, because the mean of its divisors is an integer number (370011).

2⁷⁴⁰⁰²¹ is an apocalyptic number.

It is an amenable number.

740021 is a deficient number, since it is larger than the sum of its proper divisors (1).

740021 is an equidigital number, since it uses as much as digits as its factorization.

740021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 740021 is about 860.2447326197. The cubic root of 740021 is about 90.4512725691.

Adding to 740021 its reverse (120047), we get a palindrome (860068).

The spelling of 740021 in words is "seven hundred forty thousand, twenty-one", and thus it is an iban number.