66881200997 has 8 divisors (see below), whose sum is σ = 72039489144. Its totient is φ = 61724852928.

The previous prime is 66881200993. The next prime is 66881201033. The reversal of 66881200997 is 79900218866.

It is a Cunningham number, because it is equal to 258614²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 7438372516 + 59442828481 = 86246^2 + 243809^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66881200997 - 2² = 66881200993 is a prime.

It is a super-2 number, since 2×66881200997² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66881200993) 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 7 ways as a sum of consecutive naturals, for example, 413018 + ... + 551675.

It is an arithmetic number, because the mean of its divisors is an integer number (9004936143).

Almost surely, 2^66881200997 is an apocalyptic number.

It is an amenable number.

66881200997 is a deficient number, since it is larger than the sum of its proper divisors (5158288147).

66881200997 is a wasteful number, since it uses less digits than its factorization.

66881200997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 970039.

The product of its (nonzero) digits is 2612736, while the sum is 56.

The spelling of 66881200997 in words is "sixty-six billion, eight hundred eighty-one million, two hundred thousand, nine hundred ninety-seven".