1678213129 has 4 divisors (see below), whose sum is σ = 1678361860. Its totient is φ = 1678064400.

The previous prime is 1678213111. The next prime is 1678213139. The reversal of 1678213129 is 9213128761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9213128761 = 3581 ⋅2572781.

It can be written as a sum of positive squares in 2 ways, for example, as 902702025 + 775511104 = 30045^2 + 27848^2 .

It is a cyclic number.

It is not a de Polignac number, because 1678213129 - 2¹³ = 1678204937 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1678213091 and 1678213100.

It is not an unprimeable number, because it can be changed into a prime (1678213139) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55914 + ... + 80515.

It is an arithmetic number, because the mean of its divisors is an integer number (419590465).

Almost surely, 2^1678213129 is an apocalyptic number.

It is an amenable number.

1678213129 is a deficient number, since it is larger than the sum of its proper divisors (148731).

1678213129 is a wasteful number, since it uses less digits than its factorization.

1678213129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148730.

The product of its digits is 36288, while the sum is 40.

The square root of 1678213129 is about 40965.9996704584. Note that the first 3 decimals coincide. The cubic root of 1678213129 is about 1188.3627719199.

The spelling of 1678213129 in words is "one billion, six hundred seventy-eight million, two hundred thirteen thousand, one hundred twenty-nine".