66405070399 has 2 divisors, whose sum is σ = 66405070400. Its totient is φ = 66405070398.

The previous prime is 66405070397. The next prime is 66405070447. The reversal of 66405070399 is 99307050466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66405070399 - 2¹ = 66405070397 is a prime.

It is a super-2 number, since 2×66405070399² (a number of 22 digits) contains 22 as substring.

Together with 66405070397, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66405070393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33202535199 + 33202535200.

It is an arithmetic number, because the mean of its divisors is an integer number (33202535200).

Almost surely, 2^66405070399 is an apocalyptic number.

66405070399 is a deficient number, since it is larger than the sum of its proper divisors (1).

66405070399 is an equidigital number, since it uses as much as digits as its factorization.

66405070399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1224720, while the sum is 49.

It can be divided in two parts, 664050 and 70399, that added together give a square (734449 = 857²).

The spelling of 66405070399 in words is "sixty-six billion, four hundred five million, seventy thousand, three hundred ninety-nine".