1001012001021 has 24 divisors (see below), whose sum is σ = 1529732524320. Its totient is φ = 629008855776.

The previous prime is 1001012000969. The next prime is 1001012001037. The reversal of 1001012001021 is 1201002101001.

It is a happy number.

It is not a de Polignac number, because 1001012001021 - 2³⁰ = 999938259197 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 = 1001012000994 and 1001012001012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001012001071) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14823855 + ... + 14891228.

It is an arithmetic number, because the mean of its divisors is an integer number (63738855180).

Almost surely, 2^{1001012001021} is an apocalyptic number.

It is an amenable number.

1001012001021 is a deficient number, since it is larger than the sum of its proper divisors (528720523299).

1001012001021 is a wasteful number, since it uses less digits than its factorization.

1001012001021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29715305 (or 29715302 counting only the distinct ones).

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

Adding to 1001012001021 its reverse (1201002101001), we get a palindrome (2202014102022).

The spelling of 1001012001021 in words is "one trillion, one billion, twelve million, one thousand, twenty-one".