1221211021001 has 16 divisors (see below), whose sum is σ = 1239343248000. Its totient is φ = 1203218489088.

The previous prime is 1221211020929. The next prime is 1221211021049. The reversal of 1221211021001 is 1001201121221.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221211021001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221211011001) 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, 25093670 + ... + 25142288.

It is an arithmetic number, because the mean of its divisors is an integer number (77458953000).

Almost surely, 2^{1221211021001} is an apocalyptic number.

It is an amenable number.

1221211021001 is a deficient number, since it is larger than the sum of its proper divisors (18132226999).

1221211021001 is a wasteful number, since it uses less digits than its factorization.

1221211021001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50048.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221211021001 its reverse (1001201121221), we get a palindrome (2222412142222).

The spelling of 1221211021001 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, twenty-one thousand, one".