66881200993 has 2 divisors, whose sum is σ = 66881200994. Its totient is φ = 66881200992.

The previous prime is 66881200957. The next prime is 66881201033. The reversal of 66881200993 is 39900218866.

It is a happy number.

66881200993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38256621649 + 28624579344 = 195593^2 + 169188^2 .

It is a cyclic number.

It is not a de Polignac number, because 66881200993 - 2¹⁷ = 66881069921 is a prime.

It is a super-5 number, since 5×66881200993⁵ (a number of 55 digits) contains 55555 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66881200993.

It is not a weakly prime, because it can be changed into another prime (66881207993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33440600496 + 33440600497.

It is an arithmetic number, because the mean of its divisors is an integer number (33440600497).

Almost surely, 2^66881200993 is an apocalyptic number.

It is an amenable number.

66881200993 is a deficient number, since it is larger than the sum of its proper divisors (1).

66881200993 is an equidigital number, since it uses as much as digits as its factorization.

66881200993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1119744, while the sum is 52.

The spelling of 66881200993 in words is "sixty-six billion, eight hundred eighty-one million, two hundred thousand, nine hundred ninety-three".