720680687 has 2 divisors, whose sum is σ = 720680688. Its totient is φ = 720680686.

The previous prime is 720680669. The next prime is 720680699. The reversal of 720680687 is 786086027.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 720680687 - 2¹⁴ = 720664303 is a prime.

It is a super-2 number, since 2×720680687² = 1038761305229583938, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (720680647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360340343 + 360340344.

It is an arithmetic number, because the mean of its divisors is an integer number (360340344).

Almost surely, 2^720680687 is an apocalyptic number.

720680687 is a deficient number, since it is larger than the sum of its proper divisors (1).

720680687 is an equidigital number, since it uses as much as digits as its factorization.

720680687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 225792, while the sum is 44.

The square root of 720680687 is about 26845.4965869510. The cubic root of 720680687 is about 896.5633079378.

The spelling of 720680687 in words is "seven hundred twenty million, six hundred eighty thousand, six hundred eighty-seven".