1021201001001 has 24 divisors (see below), whose sum is σ = 1481722638344. Its totient is φ = 677733765120.

The previous prime is 1021201000991. The next prime is 1021201001011. The reversal of 1021201001001 is 1001001021201.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1021201000991) and next prime (1021201001011).

It can be written as a sum of positive squares in 4 ways, for example, as 17437466601 + 1003763534400 = 132051^2 + 1001880^2 .

It is not a de Polignac number, because 1021201001001 - 2⁵ = 1021201000969 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 not an unprimeable number, because it can be changed into a prime (1021201001011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2601321 + ... + 2968041.

Almost surely, 2^{1021201001001} is an apocalyptic number.

It is an amenable number.

1021201001001 is a deficient number, since it is larger than the sum of its proper divisors (460521637343).

1021201001001 is a wasteful number, since it uses less digits than its factorization.

1021201001001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368121 (or 368118 counting only the distinct ones).

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

Adding to 1021201001001 its reverse (1001001021201), we get a palindrome (2022202022202).

The spelling of 1021201001001 in words is "one trillion, twenty-one billion, two hundred one million, one thousand, one".