720706781 has 8 divisors (see below), whose sum is σ = 729921600. Its totient is φ = 711516960.

The previous prime is 720706751. The next prime is 720706793. The reversal of 720706781 is 187607027.

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

It is a cyclic number.

It is not a de Polignac number, because 720706781 - 2⁶ = 720706717 is a prime.

It is a super-2 number, since 2×720706781² = 1038836528358763922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720706711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55640 + ... + 67358.

It is an arithmetic number, because the mean of its divisors is an integer number (91240200).

Almost surely, 2^720706781 is an apocalyptic number.

It is an amenable number.

720706781 is a deficient number, since it is larger than the sum of its proper divisors (9214819).

720706781 is a wasteful number, since it uses less digits than its factorization.

720706781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12499.

The product of its (nonzero) digits is 32928, while the sum is 38.

The square root of 720706781 is about 26845.9825858544. The cubic root of 720706781 is about 896.5741285602.

The spelling of 720706781 in words is "seven hundred twenty million, seven hundred six thousand, seven hundred eighty-one".