665715720772 has 12 divisors (see below), whose sum is σ = 1165103993340. Its totient is φ = 332828865536.

The previous prime is 665715720767. The next prime is 665715720799. The reversal of 665715720772 is 277027517566.

It can be written as a sum of positive squares in 2 ways, for example, as 424147402756 + 241568318016 = 651266^2 + 491496^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7197013 + ... + 7288924.

It is an arithmetic number, because the mean of its divisors is an integer number (97091999445).

Almost surely, 2^665715720772 is an apocalyptic number.

It is an amenable number.

665715720772 is a deficient number, since it is larger than the sum of its proper divisors (499388272568).

665715720772 is a wasteful number, since it uses less digits than its factorization.

665715720772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14497430 (or 14497428 counting only the distinct ones).

The product of its (nonzero) digits is 8643600, while the sum is 55.

The spelling of 665715720772 in words is "six hundred sixty-five billion, seven hundred fifteen million, seven hundred twenty thousand, seven hundred seventy-two".