1212212121 has 8 divisors (see below), whose sum is σ = 1621382784. Its totient is φ = 805591440.

The previous prime is 1212212119. The next prime is 1212212123. The reversal of 1212212121 is 1212122121.

It is an interprime number because it is at equal distance from previous prime (1212212119) and next prime (1212212123).

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

It is not a de Polignac number, because 1212212121 - 2¹ = 1212212119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1212212121.

It is not an unprimeable number, because it can be changed into a prime (1212212123) 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, 636385 + ... + 638286.

It is an arithmetic number, because the mean of its divisors is an integer number (202672848).

Almost surely, 2^1212212121 is an apocalyptic number.

It is an amenable number.

1212212121 is a deficient number, since it is larger than the sum of its proper divisors (409170663).

1212212121 is a wasteful number, since it uses less digits than its factorization.

1212212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274991.

The product of its digits is 32, while the sum is 15.

The square root of 1212212121 is about 34816.8367460342. The cubic root of 1212212121 is about 1066.2512191470.

Adding to 1212212121 its reverse (1212122121), we get a palindrome (2424334242).

Subtracting from 1212212121 its reverse (1212122121), we obtain a square (90000 = 300²).

The spelling of 1212212121 in words is "one billion, two hundred twelve million, two hundred twelve thousand, one hundred twenty-one".