3129985 has 4 divisors (see below), whose sum is σ = 3755988. Its totient is φ = 2503984.

The previous prime is 3129967. The next prime is 3129991. The reversal of 3129985 is 5899213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5899213 = 43 ⋅137191.

It can be written as a sum of positive squares in 2 ways, for example, as 531441 + 2598544 = 729^2 + 1612^2 .

It is a cyclic number.

It is not a de Polignac number, because 3129985 - 2⁵ = 3129953 is a prime.

It is a super-2 number, since 2×3129985² = 19593612200450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312994 + ... + 313003.

It is an arithmetic number, because the mean of its divisors is an integer number (938997).

Almost surely, 2^3129985 is an apocalyptic number.

It is an amenable number.

3129985 is a deficient number, since it is larger than the sum of its proper divisors (626003).

3129985 is an equidigital number, since it uses as much as digits as its factorization.

3129985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626002.

The product of its digits is 19440, while the sum is 37.

The square root of 3129985 is about 1769.1763620397. The cubic root of 3129985 is about 146.2785854953.

It can be divided in two parts, 3129 and 985, that added together give a palindrome (4114).

The spelling of 3129985 in words is "three million, one hundred twenty-nine thousand, nine hundred eighty-five".