128666603531 has 2 divisors, whose sum is σ = 128666603532. Its totient is φ = 128666603530.

The previous prime is 128666603497. The next prime is 128666603537. The reversal of 128666603531 is 135306666821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128666603531 - 2¹⁸ = 128666341387 is a prime.

It is a super-2 number, since 2×128666603531² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (128666603537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64333301765 + 64333301766.

It is an arithmetic number, because the mean of its divisors is an integer number (64333301766).

Almost surely, 2^128666603531 is an apocalyptic number.

128666603531 is a deficient number, since it is larger than the sum of its proper divisors (1).

128666603531 is an equidigital number, since it uses as much as digits as its factorization.

128666603531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 128666603531 in words is "one hundred twenty-eight billion, six hundred sixty-six million, six hundred three thousand, five hundred thirty-one".