20003001021 has 24 divisors (see below), whose sum is σ = 29161181400. Its totient is φ = 13212118656.

The previous prime is 20003000933. The next prime is 20003001041. The reversal of 20003001021 is 12010030002.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5665572900 + 14337428121 = 75270^2 + 119739^2 .

It is not a de Polignac number, because 20003001021 - 2⁹ = 20003000509 is a prime.

It is a super-2 number, since 2×20003001021² (a number of 21 digits) contains 22 as substring.

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 = 20003000994 and 20003001012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20003001041) 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, 513591 + ... + 551163.

It is an arithmetic number, because the mean of its divisors is an integer number (1215049225).

Almost surely, 2^20003001021 is an apocalyptic number.

It is an amenable number.

20003001021 is a deficient number, since it is larger than the sum of its proper divisors (9158180379).

20003001021 is a wasteful number, since it uses less digits than its factorization.

20003001021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38125 (or 38122 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

Adding to 20003001021 its reverse (12010030002), we get a palindrome (32013031023).

The spelling of 20003001021 in words is "twenty billion, three million, one thousand, twenty-one".