1221001022001 has 4 divisors (see below), whose sum is σ = 1628001362672. Its totient is φ = 814000681332.

The previous prime is 1221001021979. The next prime is 1221001022041. The reversal of 1221001022001 is 1002201001221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1221001022001 - 2¹³ = 1221001013809 is a prime.

It is a super-3 number, since 3×1221001022001³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221001022041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203500170331 + ... + 203500170336.

It is an arithmetic number, because the mean of its divisors is an integer number (407000340668).

Almost surely, 2^{1221001022001} is an apocalyptic number.

It is an amenable number.

1221001022001 is a deficient number, since it is larger than the sum of its proper divisors (407000340671).

1221001022001 is an equidigital number, since it uses as much as digits as its factorization.

1221001022001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407000340670.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 1221001022001 its reverse (1002201001221), we get a palindrome (2223202023222).

The spelling of 1221001022001 in words is "one trillion, two hundred twenty-one billion, one million, twenty-two thousand, one".