720740781 has 16 divisors (see below), whose sum is σ = 1077217920. Its totient is φ = 476239680.

The previous prime is 720740773. The next prime is 720740791. The reversal of 720740781 is 187047027.

It is not a de Polignac number, because 720740781 - 2³ = 720740773 is a prime.

It is a super-2 number, since 2×720740781² = 1038934546792979922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720740711) 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 15 ways as a sum of consecutive naturals, for example, 115065 + ... + 121166.

It is an arithmetic number, because the mean of its divisors is an integer number (67326120).

Almost surely, 2^720740781 is an apocalyptic number.

It is an amenable number.

720740781 is a deficient number, since it is larger than the sum of its proper divisors (356477139).

720740781 is a wasteful number, since it uses less digits than its factorization.

720740781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236353 (or 236347 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 720740781 is about 26846.6158202482. The cubic root of 720740781 is about 896.5882272393.

The spelling of 720740781 in words is "seven hundred twenty million, seven hundred forty thousand, seven hundred eighty-one".