1221002121001 has 8 divisors (see below), whose sum is σ = 1316828301824. Its totient is φ = 1125447788880.

The previous prime is 1221002120981. The next prime is 1221002121041. The reversal of 1221002121001 is 1001212001221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221002121001 - 2¹⁷ = 1221001989929 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221002121041) 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, 67952841 + ... + 67970806.

It is an arithmetic number, because the mean of its divisors is an integer number (164603537728).

Almost surely, 2^{1221002121001} is an apocalyptic number.

It is an amenable number.

1221002121001 is a deficient number, since it is larger than the sum of its proper divisors (95826180823).

1221002121001 is a wasteful number, since it uses less digits than its factorization.

1221002121001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135924351.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1221002121001 its reverse (1001212001221), we get a palindrome (2222214122222).

The spelling of 1221002121001 in words is "one trillion, two hundred twenty-one billion, two million, one hundred twenty-one thousand, one".