666557377753 has 2 divisors, whose sum is σ = 666557377754. Its totient is φ = 666557377752.

The previous prime is 666557377711. The next prime is 666557377757. The reversal of 666557377753 is 357773755666.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 635612346009 + 30945031744 = 797253^2 + 175912^2 .

It is a cyclic number.

It is not a de Polignac number, because 666557377753 - 2¹⁷ = 666557246681 is a prime.

It is not a weakly prime, because it can be changed into another prime (666557377757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333278688876 + 333278688877.

It is an arithmetic number, because the mean of its divisors is an integer number (333278688877).

Almost surely, 2^666557377753 is an apocalyptic number.

It is an amenable number.

666557377753 is a deficient number, since it is larger than the sum of its proper divisors (1).

666557377753 is an equidigital number, since it uses as much as digits as its factorization.

666557377753 is an evil number, because the sum of its binary digits is even.

The product of its digits is 583443000, while the sum is 67.

The spelling of 666557377753 in words is "six hundred sixty-six billion, five hundred fifty-seven million, three hundred seventy-seven thousand, seven hundred fifty-three".