720610521 has 8 divisors (see below), whose sum is σ = 973976160. Its totient is φ = 473825952.

The previous prime is 720610519. The next prime is 720610523. The reversal of 720610521 is 125016027.

It is an interprime number because it is at equal distance from previous prime (720610519) and next prime (720610523).

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

It is not a de Polignac number, because 720610521 - 2¹ = 720610519 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 720610491 and 720610500.

It is not an unprimeable number, because it can be changed into a prime (720610523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1645011 + ... + 1645448.

It is an arithmetic number, because the mean of its divisors is an integer number (121747020).

Almost surely, 2^720610521 is an apocalyptic number.

It is an amenable number.

720610521 is a deficient number, since it is larger than the sum of its proper divisors (253365639).

720610521 is a wasteful number, since it uses less digits than its factorization.

720610521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3290535.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 720610521 is about 26844.1897065268. The cubic root of 720610521 is about 896.5342103065.

Adding to 720610521 its reverse (125016027), we get a palindrome (845626548).

The spelling of 720610521 in words is "seven hundred twenty million, six hundred ten thousand, five hundred twenty-one".