3121020043213 has 4 divisors (see below), whose sum is σ = 3121037700508. Its totient is φ = 3121002385920.

The previous prime is 3121020043187. The next prime is 3121020043223. The reversal of 3121020043213 is 3123400201213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1141826884969 + 1979193158244 = 1068563^2 + 1406838^2 .

It is a cyclic number.

It is not a de Polignac number, because 3121020043213 - 2¹⁷ = 3121019912141 is a prime.

It is a super-2 number, since 2×3121020043213² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3121020043223) 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, 8560806 + ... + 8917927.

It is an arithmetic number, because the mean of its divisors is an integer number (780259425127).

Almost surely, 2^{3121020043213} is an apocalyptic number.

It is an amenable number.

3121020043213 is a deficient number, since it is larger than the sum of its proper divisors (17657295).

3121020043213 is a wasteful number, since it uses less digits than its factorization.

3121020043213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17657294.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 3121020043213 its reverse (3123400201213), we get a palindrome (6244420244426).

The spelling of 3121020043213 in words is "three trillion, one hundred twenty-one billion, twenty million, forty-three thousand, two hundred thirteen".