1212121201 has 4 divisors (see below), whose sum is σ = 1223889472. Its totient is φ = 1200352932.

The previous prime is 1212121181. The next prime is 1212121217. The reversal of 1212121201 is 1021212121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1021212121 = 23 ⋅44400527.

It is a cyclic number.

It is not a de Polignac number, because 1212121201 - 2¹⁵ = 1212088433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1212121231) 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 3 ways as a sum of consecutive naturals, for example, 5883981 + ... + 5884186.

It is an arithmetic number, because the mean of its divisors is an integer number (305972368).

Almost surely, 2^1212121201 is an apocalyptic number.

It is an amenable number.

1212121201 is a deficient number, since it is larger than the sum of its proper divisors (11768271).

1212121201 is a wasteful number, since it uses less digits than its factorization.

1212121201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11768270.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1212121201 is about 34815.5310314233. The cubic root of 1212121201 is about 1066.2245610006.

Adding to 1212121201 its reverse (1021212121), we get a palindrome (2233333322).

It can be divided in two parts, 121212120 and 1, that added together give a palindrome (121212121).

The spelling of 1212121201 in words is "one billion, two hundred twelve million, one hundred twenty-one thousand, two hundred one".