121211211221001 has 36 divisors (see below), whose sum is σ = 192465237637764. Its totient is φ = 73454168504640.

The previous prime is 121211211220973. The next prime is 121211211221003. The reversal of 121211211221001 is 100122112112121.

It is a happy number.

121211211221001 is a `hidden beast` number, since 1 + 21 + 211 + 211 + 221 + 0 + 0 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21101160960000 + 100110050261001 = 4593600^2 + 10005501^2 .

It is not a de Polignac number, because 121211211221001 - 2¹¹ = 121211211218953 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121211211221003) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5737591 + ... + 16593443.

It is an arithmetic number, because the mean of its divisors is an integer number (5346256601049).

Almost surely, 2^{121211211221001} is an apocalyptic number.

121211211221001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121211211221001 is a deficient number, since it is larger than the sum of its proper divisors (71254026416763).

121211211221001 is a wasteful number, since it uses less digits than its factorization.

121211211221001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10866134 (or 10866120 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 121211211221001 its reverse (100122112112121), we get a palindrome (221333323333122).

The spelling of 121211211221001 in words is "one hundred twenty-one trillion, two hundred eleven billion, two hundred eleven million, two hundred twenty-one thousand, one".