1221002000001 has 48 divisors (see below), whose sum is σ = 2041907212800. Its totient is φ = 688623496704.

The previous prime is 1221001999993. The next prime is 1221002000033. The reversal of 1221002000001 is 1000002001221.

It is not a de Polignac number, because 1221002000001 - 2³ = 1221001999993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (1221002000041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13537285 + ... + 13627181.

It is an arithmetic number, because the mean of its divisors is an integer number (42539733600).

Almost surely, 2^{1221002000001} is an apocalyptic number.

It is an amenable number.

1221002000001 is a deficient number, since it is larger than the sum of its proper divisors (820905212799).

1221002000001 is a wasteful number, since it uses less digits than its factorization.

1221002000001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92718 (or 92715 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1221002000001 its reverse (1000002001221), we get a palindrome (2221004001222).

The spelling of 1221002000001 in words is "one trillion, two hundred twenty-one billion, two million, one", and thus it is an aban number.