66317393 has 2 divisors, whose sum is σ = 66317394. Its totient is φ = 66317392.

The previous prime is 66317389. The next prime is 66317399. The reversal of 66317393 is 39371366.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66064384 + 253009 = 8128^2 + 503^2 .

It is a cyclic number.

It is not a de Polignac number, because 66317393 - 2² = 66317389 is a prime.

It is a super-2 number, since 2×66317393² = 8795993228632898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66317399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33158696 + 33158697.

It is an arithmetic number, because the mean of its divisors is an integer number (33158697).

Almost surely, 2^66317393 is an apocalyptic number.

It is an amenable number.

66317393 is a deficient number, since it is larger than the sum of its proper divisors (1).

66317393 is an equidigital number, since it uses as much as digits as its factorization.

66317393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61236, while the sum is 38.

The square root of 66317393 is about 8143.5491648298. The cubic root of 66317393 is about 404.7707751278.

The spelling of 66317393 in words is "sixty-six million, three hundred seventeen thousand, three hundred ninety-three".