720953991 has 12 divisors (see below), whose sum is σ = 1069523832. Its totient is φ = 467645616.

The previous prime is 720953983. The next prime is 720954001. The reversal of 720953991 is 199359027.

It is a happy number.

720953991 is a `hidden beast` number, since 7 + 20 + 9 + 539 + 91 = 666.

It is not a de Polignac number, because 720953991 - 2³ = 720953983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720953971) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1082181 + ... + 1082846.

It is an arithmetic number, because the mean of its divisors is an integer number (89126986).

Almost surely, 2^720953991 is an apocalyptic number.

720953991 is a deficient number, since it is larger than the sum of its proper divisors (348569841).

720953991 is a wasteful number, since it uses less digits than its factorization.

720953991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2165070 (or 2165067 counting only the distinct ones).

The product of its (nonzero) digits is 153090, while the sum is 45.

The square root of 720953991 is about 26850.5864181772. The cubic root of 720953991 is about 896.6766282911.

The spelling of 720953991 in words is "seven hundred twenty million, nine hundred fifty-three thousand, nine hundred ninety-one".