1211002121 has 24 divisors (see below), whose sum is σ = 1437204384. Its totient is φ = 1017219840.

The previous prime is 1211002043. The next prime is 1211002159. The reversal of 1211002121 is 1212001121.

It is not a de Polignac number, because 1211002121 - 2¹⁸ = 1210739977 is a prime.

It is a super-2 number, since 2×1211002121² = 2933052274132997282, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1211002181) 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 23 ways as a sum of consecutive naturals, for example, 531641 + ... + 533913.

It is an arithmetic number, because the mean of its divisors is an integer number (59883516).

Almost surely, 2^1211002121 is an apocalyptic number.

It is an amenable number.

1211002121 is a deficient number, since it is larger than the sum of its proper divisors (226202263).

1211002121 is a wasteful number, since it uses less digits than its factorization.

1211002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2501 (or 2494 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1211002121 is about 34799.4557572385. The cubic root of 1211002121 is about 1065.8963325555.

Adding to 1211002121 its reverse (1212001121), we get a palindrome (2423003242).

The spelling of 1211002121 in words is "one billion, two hundred eleven million, two thousand, one hundred twenty-one".