66319081 has 2 divisors, whose sum is σ = 66319082. Its totient is φ = 66319080.

The previous prime is 66319073. The next prime is 66319093. The reversal of 66319081 is 18091366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49843600 + 16475481 = 7060^2 + 4059^2 .

It is a cyclic number.

It is not a de Polignac number, because 66319081 - 2³ = 66319073 is a prime.

It is a super-2 number, since 2×66319081² = 8796441009369122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66319381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33159540 + 33159541.

It is an arithmetic number, because the mean of its divisors is an integer number (33159541).

Almost surely, 2^66319081 is an apocalyptic number.

It is an amenable number.

66319081 is a deficient number, since it is larger than the sum of its proper divisors (1).

66319081 is an equidigital number, since it uses as much as digits as its factorization.

66319081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 66319081 is about 8143.6528044852. The cubic root of 66319081 is about 404.7742093565.

The spelling of 66319081 in words is "sixty-six million, three hundred nineteen thousand, eighty-one".