1011020021001 has 16 divisors (see below), whose sum is σ = 1511805643200. Its totient is φ = 667714155264.

The previous prime is 1011020020999. The next prime is 1011020021003. The reversal of 1011020021001 is 1001200201101.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1011020020999) and next prime (1011020021003).

It is not a de Polignac number, because 1011020021001 - 2¹ = 1011020020999 is a prime.

It is a super-2 number, since 2×1011020021001² (a number of 25 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (1011020021003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174974616 + ... + 174980393.

It is an arithmetic number, because the mean of its divisors is an integer number (94487852700).

Almost surely, 2^{1011020021001} is an apocalyptic number.

It is an amenable number.

1011020021001 is a deficient number, since it is larger than the sum of its proper divisors (500785622199).

1011020021001 is a wasteful number, since it uses less digits than its factorization.

1011020021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349955125 (or 349955119 counting only the distinct ones).

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

Adding to 1011020021001 its reverse (1001200201101), we get a palindrome (2012220222102).

The spelling of 1011020021001 in words is "one trillion, eleven billion, twenty million, twenty-one thousand, one".