720665565673 has 4 divisors (see below), whose sum is σ = 723897250048. Its totient is φ = 717433881300.

The previous prime is 720665565671. The next prime is 720665565689. The reversal of 720665565673 is 376565566027.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 376565566027 = 7 ⋅53795080861.

It is a cyclic number.

It is not a de Polignac number, because 720665565673 - 2¹ = 720665565671 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (720665565671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1615841853 + ... + 1615842298.

It is an arithmetic number, because the mean of its divisors is an integer number (180974312512).

Almost surely, 2^720665565673 is an apocalyptic number.

It is an amenable number.

720665565673 is a deficient number, since it is larger than the sum of its proper divisors (3231684375).

720665565673 is a wasteful number, since it uses less digits than its factorization.

720665565673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3231684374.

The product of its (nonzero) digits is 47628000, while the sum is 58.

The spelling of 720665565673 in words is "seven hundred twenty billion, six hundred sixty-five million, five hundred sixty-five thousand, six hundred seventy-three".