720651 has 16 divisors (see below), whose sum is σ = 1036800. Its totient is φ = 443808.

The previous prime is 720619. The next prime is 720653. The reversal of 720651 is 156027.

It is not a de Polignac number, because 720651 - 2⁵ = 720619 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (720653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2545 + ... + 2813.

It is an arithmetic number, because the mean of its divisors is an integer number (64800).

2⁷²⁰⁶⁵¹ is an apocalyptic number.

720651 is a deficient number, since it is larger than the sum of its proper divisors (316149).

720651 is a wasteful number, since it uses less digits than its factorization.

720651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 720651 is about 848.9116561810. The cubic root of 720651 is about 89.6550997058.

Adding to 720651 its reverse (156027), we get a palindrome (876678).

The spelling of 720651 in words is "seven hundred twenty thousand, six hundred fifty-one".