660722516221 has 4 divisors (see below), whose sum is σ = 660724599744. Its totient is φ = 660720432700.

The previous prime is 660722516203. The next prime is 660722516227. The reversal of 660722516221 is 122615227066.

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.

It is a cyclic number.

It is not a de Polignac number, because 660722516221 - 2¹⁵ = 660722483453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660722516227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 456475 + ... + 1236856.

It is an arithmetic number, because the mean of its divisors is an integer number (165181149936).

Almost surely, 2^660722516221 is an apocalyptic number.

It is an amenable number.

660722516221 is a deficient number, since it is larger than the sum of its proper divisors (2083523).

660722516221 is a wasteful number, since it uses less digits than its factorization.

660722516221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2083522.

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 660722516221 in words is "six hundred sixty billion, seven hundred twenty-two million, five hundred sixteen thousand, two hundred twenty-one".