2129812813 has 4 divisors (see below), whose sum is σ = 2148660828. Its totient is φ = 2110964800.

The previous prime is 2129812799. The next prime is 2129812843. The reversal of 2129812813 is 3182189212.

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 100040004 + 2029772809 = 10002^2 + 45053^2 .

It is a cyclic number.

It is not a de Polignac number, because 2129812813 - 2⁹ = 2129812301 is a prime.

It is a super-3 number, since 3×2129812813³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2129812843) 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, 9423838 + ... + 9424063.

It is an arithmetic number, because the mean of its divisors is an integer number (537165207).

Almost surely, 2^2129812813 is an apocalyptic number.

It is an amenable number.

2129812813 is a deficient number, since it is larger than the sum of its proper divisors (18848015).

2129812813 is a wasteful number, since it uses less digits than its factorization.

2129812813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18848014.

The product of its digits is 13824, while the sum is 37.

The square root of 2129812813 is about 46149.8950486347. The cubic root of 2129812813 is about 1286.6106593770.

The spelling of 2129812813 in words is "two billion, one hundred twenty-nine million, eight hundred twelve thousand, eight hundred thirteen".