720637858685 has 4 divisors (see below), whose sum is σ = 864765430428. Its totient is φ = 576510286944.

The previous prime is 720637858663. The next prime is 720637858747. The reversal of 720637858685 is 586858736027.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 586858736027 = 1511 ⋅388390957.

It can be written as a sum of positive squares in 2 ways, for example, as 272323247716 + 448314610969 = 521846^2 + 669563^2 .

It is a cyclic number.

It is not a de Polignac number, because 720637858685 - 2⁶ = 720637858621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72063785864 + ... + 72063785873.

It is an arithmetic number, because the mean of its divisors is an integer number (216191357607).

Almost surely, 2^720637858685 is an apocalyptic number.

It is an amenable number.

720637858685 is a deficient number, since it is larger than the sum of its proper divisors (144127571743).

720637858685 is a wasteful number, since it uses less digits than its factorization.

720637858685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144127571742.

The product of its (nonzero) digits is 135475200, while the sum is 65.

The spelling of 720637858685 in words is "seven hundred twenty billion, six hundred thirty-seven million, eight hundred fifty-eight thousand, six hundred eighty-five".