1221010221001 has 8 divisors (see below), whose sum is σ = 1222211045000. Its totient is φ = 1219809756672.

The previous prime is 1221010220993. The next prime is 1221010221023. The reversal of 1221010221001 is 1001220101221.

It can be written as a sum of positive squares in 4 ways, for example, as 270999371776 + 950010849225 = 520576^2 + 974685^2 .

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 1221010221001 - 2³ = 1221010220993 is a prime.

It is a super-2 number, since 2×1221010221001² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221010221401) 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, 6974131 + ... + 7147063.

It is an arithmetic number, because the mean of its divisors is an integer number (152776380625).

Almost surely, 2^{1221010221001} is an apocalyptic number.

It is an amenable number.

1221010221001 is a deficient number, since it is larger than the sum of its proper divisors (1200823999).

1221010221001 is a wasteful number, since it uses less digits than its factorization.

1221010221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179835.

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

Adding to 1221010221001 its reverse (1001220101221), we get a palindrome (2222230322222).

The spelling of 1221010221001 in words is "one trillion, two hundred twenty-one billion, ten million, two hundred twenty-one thousand, one".