720945 has 24 divisors (see below), whose sum is σ = 1286376. Its totient is φ = 373248.

The previous prime is 720943. The next prime is 720947. The reversal of 720945 is 549027.

720945 is nontrivially palindromic in base 14.

It is an interprime number because it is at equal distance from previous prime (720943) and next prime (720947).

It can be written as a sum of positive squares in 4 ways, for example, as 74529 + 646416 = 273^2 + 804^2 .

It is not a de Polignac number, because 720945 - 2¹ = 720943 is a prime.

It is a super-3 number, since 3×720945³ = 1124158781333725875, which contains 333 as substring.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 720945.

It is not an unprimeable number, because it can be changed into a prime (720943) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1449 + ... + 1881.

It is an arithmetic number, because the mean of its divisors is an integer number (53599).

2⁷²⁰⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

720945 is a deficient number, since it is larger than the sum of its proper divisors (565431).

720945 is a wasteful number, since it uses less digits than its factorization.

720945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481 (or 478 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 720945 is about 849.0848014186. The cubic root of 720945 is about 89.6672900798.

The spelling of 720945 in words is "seven hundred twenty thousand, nine hundred forty-five".