66377881 has 2 divisors, whose sum is σ = 66377882. Its totient is φ = 66377880.

The previous prime is 66377863. The next prime is 66377923. The reversal of 66377881 is 18877366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38192400 + 28185481 = 6180^2 + 5309^2 .

It is a cyclic number.

It is not a de Polignac number, because 66377881 - 2¹³ = 66369689 is a prime.

It is a super-2 number, since 2×66377881² = 8812046172100322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66377081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33188940 + 33188941.

It is an arithmetic number, because the mean of its divisors is an integer number (33188941).

Almost surely, 2^66377881 is an apocalyptic number.

It is an amenable number.

66377881 is a deficient number, since it is larger than the sum of its proper divisors (1).

66377881 is an equidigital number, since it uses as much as digits as its factorization.

66377881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 46.

The square root of 66377881 is about 8147.2621781799. The cubic root of 66377881 is about 404.8938013478.

The spelling of 66377881 in words is "sixty-six million, three hundred seventy-seven thousand, eight hundred eighty-one".