321686137 has 2 divisors, whose sum is σ = 321686138. Its totient is φ = 321686136.

The previous prime is 321686117. The next prime is 321686149. The reversal of 321686137 is 731686123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 207965241 + 113720896 = 14421^2 + 10664^2 .

It is a cyclic number.

It is not a de Polignac number, because 321686137 - 2¹⁵ = 321653369 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 321686096 and 321686105.

It is not a weakly prime, because it can be changed into another prime (321686117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160843068 + 160843069.

It is an arithmetic number, because the mean of its divisors is an integer number (160843069).

Almost surely, 2^321686137 is an apocalyptic number.

It is an amenable number.

321686137 is a deficient number, since it is larger than the sum of its proper divisors (1).

321686137 is an equidigital number, since it uses as much as digits as its factorization.

321686137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 37.

The square root of 321686137 is about 17935.6108621926. The cubic root of 321686137 is about 685.1896304871.

The spelling of 321686137 in words is "three hundred twenty-one million, six hundred eighty-six thousand, one hundred thirty-seven".