1001000101221 has 20 divisors (see below), whose sum is σ = 1495352268652. Its totient is φ = 667319508288.

The previous prime is 1001000101183. The next prime is 1001000101223. The reversal of 1001000101221 is 1221010001001.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 676226628900 + 324773472321 = 822330^2 + 569889^2 .

It is not a de Polignac number, because 1001000101221 - 2¹³ = 1001000093029 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001000101223) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5080275 + ... + 5273631.

Almost surely, 2^{1001000101221} is an apocalyptic number.

It is an amenable number.

1001000101221 is a deficient number, since it is larger than the sum of its proper divisors (494352167431).

1001000101221 is an equidigital number, since it uses as much as digits as its factorization.

1001000101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257282 (or 257273 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1001000101221 its reverse (1221010001001), we get a palindrome (2222010102222).

The spelling of 1001000101221 in words is "one trillion, one billion, one hundred one thousand, two hundred twenty-one".