212121013 has 8 divisors (see below), whose sum is σ = 228709656. Its totient is φ = 195571200.

The previous prime is 212120983. The next prime is 212121023. The reversal of 212121013 is 310121212.

It can be written as a sum of positive squares in 4 ways, for example, as 28708164 + 183412849 = 5358^2 + 13543^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212121013 - 2⁹ = 212120501 is a prime.

It is a super-3 number, since 3×212121013³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212120984 and 212121002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2193 + ... + 20713.

It is an arithmetic number, because the mean of its divisors is an integer number (28588707).

Almost surely, 2^212121013 is an apocalyptic number.

It is an amenable number.

212121013 is a deficient number, since it is larger than the sum of its proper divisors (16588643).

212121013 is a wasteful number, since it uses less digits than its factorization.

212121013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19415.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 212121013 is about 14564.3747891902. The cubic root of 212121013 is about 596.3866282951.

Adding to 212121013 its reverse (310121212), we get a palindrome (522242225).

The spelling of 212121013 in words is "two hundred twelve million, one hundred twenty-one thousand, thirteen".