660221473757 has 4 divisors (see below), whose sum is σ = 660223264416. Its totient is φ = 660219683100.

The previous prime is 660221473711. The next prime is 660221473819. The reversal of 660221473757 is 757374122066.

660221473757 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 660221473757 - 2¹⁴ = 660221457373 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 (660221473357) 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, 116369 + ... + 1154982.

It is an arithmetic number, because the mean of its divisors is an integer number (165055816104).

Almost surely, 2^660221473757 is an apocalyptic number.

It is an amenable number.

660221473757 is a deficient number, since it is larger than the sum of its proper divisors (1790659).

660221473757 is a wasteful number, since it uses less digits than its factorization.

660221473757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1790658.

The product of its (nonzero) digits is 2963520, while the sum is 50.

The spelling of 660221473757 in words is "six hundred sixty billion, two hundred twenty-one million, four hundred seventy-three thousand, seven hundred fifty-seven".