1020001011021 has 16 divisors (see below), whose sum is σ = 1513905814720. Its totient is φ = 678743731440.

The previous prime is 1020001011017. The next prime is 1020001011031. The reversal of 1020001011021 is 1201101000201.

It is a happy number.

It is not a de Polignac number, because 1020001011021 - 2² = 1020001011017 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 junction number, because it is equal to n+sod(n) for n = 1020001010994 and 1020001011012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020001011031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34900195 + ... + 34929408.

It is an arithmetic number, because the mean of its divisors is an integer number (94619113420).

Almost surely, 2^{1020001011021} is an apocalyptic number.

It is an amenable number.

1020001011021 is a deficient number, since it is larger than the sum of its proper divisors (493904803699).

1020001011021 is an equidigital number, since it uses as much as digits as its factorization.

1020001011021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69830153 (or 69830147 counting only the distinct ones).

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

Adding to 1020001011021 its reverse (1201101000201), we get a palindrome (2221102011222).

The spelling of 1020001011021 in words is "one trillion, twenty billion, one million, eleven thousand, twenty-one".