720421 has 8 divisors (see below), whose sum is σ = 783104. Its totient is φ = 658800.

The previous prime is 720413. The next prime is 720439. The reversal of 720421 is 124027.

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

It is a cyclic number.

It is not a de Polignac number, because 720421 - 2³ = 720413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 720395 and 720404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1780 + ... + 2146.

It is an arithmetic number, because the mean of its divisors is an integer number (97888).

2⁷²⁰⁴²¹ is an apocalyptic number.

It is an amenable number.

720421 is a deficient number, since it is larger than the sum of its proper divisors (62683).

720421 is a wasteful number, since it uses less digits than its factorization.

720421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 531.

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 720421 is about 848.7761777995. The cubic root of 720421 is about 89.6455607070.

Adding to 720421 its reverse (124027), we get a palindrome (844448).

It can be divided in two parts, 7204 and 21, that added together give a square (7225 = 85²).

The spelling of 720421 in words is "seven hundred twenty thousand, four hundred twenty-one", and thus it is an iban number.