66912401 has 2 divisors, whose sum is σ = 66912402. Its totient is φ = 66912400.

The previous prime is 66912389. The next prime is 66912403. The reversal of 66912401 is 10421966.

It is a Cunningham number, because it is equal to 8180²+1.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66912400 + 1 = 8180^2 + 1^2 .

It is a cyclic number.

It is not a de Polignac number, because 66912401 - 2⁶ = 66912337 is a prime.

Together with 66912403, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66912403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33456200 + 33456201.

It is an arithmetic number, because the mean of its divisors is an integer number (33456201).

Almost surely, 2^66912401 is an apocalyptic number.

It is an amenable number.

66912401 is a deficient number, since it is larger than the sum of its proper divisors (1).

66912401 is an equidigital number, since it uses as much as digits as its factorization.

66912401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 66912401 is about 8180.0000611247. Note that the first 4 decimals coincide. The cubic root of 66912401 is about 405.9777241129.

The spelling of 66912401 in words is "sixty-six million, nine hundred twelve thousand, four hundred one".