665156117 has 2 divisors, whose sum is σ = 665156118. Its totient is φ = 665156116.

The previous prime is 665156111. The next prime is 665156131. The reversal of 665156117 is 711651566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 581726161 + 83429956 = 24119^2 + 9134^2 .

It is a cyclic number.

It is not a de Polignac number, because 665156117 - 2⁶ = 665156053 is a prime.

It is a super-4 number, since 4×665156117⁴ (a number of 36 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665156111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332578058 + 332578059.

It is an arithmetic number, because the mean of its divisors is an integer number (332578059).

Almost surely, 2^665156117 is an apocalyptic number.

It is an amenable number.

665156117 is a deficient number, since it is larger than the sum of its proper divisors (1).

665156117 is an equidigital number, since it uses as much as digits as its factorization.

665156117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37800, while the sum is 38.

The square root of 665156117 is about 25790.6207176175. The cubic root of 665156117 is about 872.9201724429.

The spelling of 665156117 in words is "six hundred sixty-five million, one hundred fifty-six thousand, one hundred seventeen".