66401077 has 2 divisors, whose sum is σ = 66401078. Its totient is φ = 66401076.

The previous prime is 66401063. The next prime is 66401081. The reversal of 66401077 is 77010466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66161956 + 239121 = 8134^2 + 489^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66401077 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, 33200538 + 33200539.

It is an arithmetic number, because the mean of its divisors is an integer number (33200539).

Almost surely, 2^66401077 is an apocalyptic number.

It is an amenable number.

66401077 is a deficient number, since it is larger than the sum of its proper divisors (1).

66401077 is an equidigital number, since it uses as much as digits as its factorization.

66401077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 66401077 is about 8148.6855995308. The cubic root of 66401077 is about 404.9409597419.

The spelling of 66401077 in words is "sixty-six million, four hundred one thousand, seventy-seven".