66401407 has 2 divisors, whose sum is σ = 66401408. Its totient is φ = 66401406.

The previous prime is 66401389. The next prime is 66401429. The reversal of 66401407 is 70410466.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66401407 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66401477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33200703 + 33200704.

It is an arithmetic number, because the mean of its divisors is an integer number (33200704).

Almost surely, 2^66401407 is an apocalyptic number.

66401407 is a deficient number, since it is larger than the sum of its proper divisors (1).

66401407 is an equidigital number, since it uses as much as digits as its factorization.

66401407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 66401407 is about 8148.7058481700. The cubic root of 66401407 is about 404.9416305659.

The spelling of 66401407 in words is "sixty-six million, four hundred one thousand, four hundred seven".