3129689 has 2 divisors, whose sum is σ = 3129690. Its totient is φ = 3129688.

The previous prime is 3129677. The next prime is 3129691. The reversal of 3129689 is 9869213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2274064 + 855625 = 1508^2 + 925^2 .

It is a cyclic number.

It is not a de Polignac number, because 3129689 - 2¹² = 3125593 is a prime.

Together with 3129691, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3129619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1564844 + 1564845.

It is an arithmetic number, because the mean of its divisors is an integer number (1564845).

Almost surely, 2^3129689 is an apocalyptic number.

It is an amenable number.

3129689 is a deficient number, since it is larger than the sum of its proper divisors (1).

3129689 is an equidigital number, since it uses as much as digits as its factorization.

3129689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 38.

The square root of 3129689 is about 1769.0927053154. The cubic root of 3129689 is about 146.2739742031.

It can be divided in two parts, 312 and 9689, that added together give a palindrome (10001).

The spelling of 3129689 in words is "three million, one hundred twenty-nine thousand, six hundred eighty-nine".