3121121689 has 27 divisors (see below), whose sum is σ = 3806381397. Its totient is φ = 2551557624.

The previous prime is 3121121657. The next prime is 3121121699. The reversal of 3121121689 is 9861211213.

The square root of 3121121689 is 55867.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 3121121689 - 2⁵ = 3121121657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3121121609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 8994414 + ... + 8994760.

Almost surely, 2^3121121689 is an apocalyptic number.

3121121689 is the 55867-th square number.

3121121689 is the 27934-th centered octagonal number.

It is an amenable number.

3121121689 is a deficient number, since it is larger than the sum of its proper divisors (685259708).

3121121689 is an frugal number, since it uses more digits than its factorization.

3121121689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 754 (or 377 counting only the distinct ones).

The product of its digits is 5184, while the sum is 34.

The cubic root of 3121121689 is about 1461.4038053889.

Multiplying 3121121689 by its product of digits (5184), we get a square (16179894835776 = 4022424²).

It can be divided in two parts, 31211 and 21689, that added together give a square (52900 = 230²).

The spelling of 3121121689 in words is "three billion, one hundred twenty-one million, one hundred twenty-one thousand, six hundred eighty-nine".