1221201011001 has 8 divisors (see below), whose sum is σ = 1628273866464. Its totient is φ = 814131081440.

The previous prime is 1221201010993. The next prime is 1221201011101. The reversal of 1221201011001 is 1001101021221.

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 1221201011001 - 2³ = 1221201010993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221201011101) 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, 576550 + ... + 1665776.

It is an arithmetic number, because the mean of its divisors is an integer number (203534233308).

Almost surely, 2^{1221201011001} is an apocalyptic number.

It is an amenable number.

1221201011001 is a deficient number, since it is larger than the sum of its proper divisors (407072855463).

1221201011001 is a wasteful number, since it uses less digits than its factorization.

1221201011001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1462951.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1221201011001 its reverse (1001101021221), we get a palindrome (2222302032222).

The spelling of 1221201011001 in words is "one trillion, two hundred twenty-one billion, two hundred one million, eleven thousand, one".