1001001120021 has 96 divisors (see below), whose sum is σ = 1736511049728. Its totient is φ = 543267648000.

The previous prime is 1001001120013. The next prime is 1001001120023. The reversal of 1001001120021 is 1200211001001.

It is a happy number.

It is not a de Polignac number, because 1001001120021 - 2³ = 1001001120013 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 1001001119985 and 1001001120012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001001120023) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 122562480 + ... + 122570646.

It is an arithmetic number, because the mean of its divisors is an integer number (18088656768).

Almost surely, 2^{1001001120021} is an apocalyptic number.

It is an amenable number.

1001001120021 is a deficient number, since it is larger than the sum of its proper divisors (735509929707).

1001001120021 is a wasteful number, since it uses less digits than its factorization.

1001001120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8791 (or 8788 counting only the distinct ones).

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

Adding to 1001001120021 its reverse (1200211001001), we get a palindrome (2201212121022).

It can be divided in two parts, 1001001 and 120021, that multiplied together give a palindrome (120141141021).

The spelling of 1001001120021 in words is "one trillion, one billion, one million, one hundred twenty thousand, twenty-one".