665606237 has 2 divisors, whose sum is σ = 665606238. Its totient is φ = 665606236.

The previous prime is 665606213. The next prime is 665606251. The reversal of 665606237 is 732606566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 571496836 + 94109401 = 23906^2 + 9701^2 .

It is a cyclic number.

It is not a de Polignac number, because 665606237 - 2¹² = 665602141 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665606194 and 665606203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665606257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332803118 + 332803119.

It is an arithmetic number, because the mean of its divisors is an integer number (332803119).

Almost surely, 2^665606237 is an apocalyptic number.

It is an amenable number.

665606237 is a deficient number, since it is larger than the sum of its proper divisors (1).

665606237 is an equidigital number, since it uses as much as digits as its factorization.

665606237 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 41.

The square root of 665606237 is about 25799.3456699971. The cubic root of 665606237 is about 873.1170336108.

The spelling of 665606237 in words is "six hundred sixty-five million, six hundred six thousand, two hundred thirty-seven".