20120021001 has 10 divisors (see below), whose sum is σ = 30055833962. Its totient is φ = 13413347280.

The previous prime is 20120020993. The next prime is 20120021023. The reversal of 20120021001 is 10012002102.

It can be written as a sum of positive squares in only one way, i.e., 18872165376 + 1247855625 = 137376^2 + 35325^2 .

It is not a de Polignac number, because 20120021001 - 2³ = 20120020993 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 not an unprimeable number, because it can be changed into a prime (20120001001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 124197580 + ... + 124197741.

Almost surely, 2^20120021001 is an apocalyptic number.

It is an amenable number.

20120021001 is a deficient number, since it is larger than the sum of its proper divisors (9935812961).

20120021001 is an equidigital number, since it uses as much as digits as its factorization.

20120021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248395333 (or 248395324 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 20120021001 its reverse (10012002102), we get a palindrome (30132023103).

The spelling of 20120021001 in words is "twenty billion, one hundred twenty million, twenty-one thousand, one".