121212021 has 16 divisors (see below), whose sum is σ = 184883328. Its totient is φ = 69196800.

The previous prime is 121212017. The next prime is 121212071. The reversal of 121212021 is 120212121.

It is not a de Polignac number, because 121212021 - 2² = 121212017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121211988 and 121212006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26461 + ... + 30701.

It is an arithmetic number, because the mean of its divisors is an integer number (11555208).

Almost surely, 2^121212021 is an apocalyptic number.

It is an amenable number.

121212021 is a deficient number, since it is larger than the sum of its proper divisors (63671307).

121212021 is a wasteful number, since it uses less digits than its factorization.

121212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5612.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 121212021 is about 11009.6331001537. The cubic root of 121212021 is about 494.8974667744.

Adding to 121212021 its reverse (120212121), we get a palindrome (241424142).

The spelling of 121212021 in words is "one hundred twenty-one million, two hundred twelve thousand, twenty-one".