66690431501 has 2 divisors, whose sum is σ = 66690431502. Its totient is φ = 66690431500.

The previous prime is 66690431459. The next prime is 66690431519. The reversal of 66690431501 is 10513409666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36271583401 + 30418848100 = 190451^2 + 174410^2 .

It is a cyclic number.

It is not a de Polignac number, because 66690431501 - 2²² = 66686237197 is a prime.

It is a super-2 number, since 2×66690431501² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66690431551) 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 as a sum of consecutive naturals, namely, 33345215750 + 33345215751.

It is an arithmetic number, because the mean of its divisors is an integer number (33345215751).

Almost surely, 2^66690431501 is an apocalyptic number.

It is an amenable number.

66690431501 is a deficient number, since it is larger than the sum of its proper divisors (1).

66690431501 is an equidigital number, since it uses as much as digits as its factorization.

66690431501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 41.

The spelling of 66690431501 in words is "sixty-six billion, six hundred ninety million, four hundred thirty-one thousand, five hundred one".