20120111001 has 6 divisors (see below), whose sum is σ = 29062382570. Its totient is φ = 13413407328.

The previous prime is 20120110981. The next prime is 20120111003. The reversal of 20120111001 is 10011102102.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18530015625 + 1590095376 = 136125^2 + 39876^2 .

It is not a de Polignac number, because 20120111001 - 2⁷ = 20120110873 is a prime.

It is a super-2 number, since 2×20120111001² (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), and also a Moran number because the ratio is a prime number: 2235567889 = 20120111001 / (2 + 0 + 1 + 2 + 0 + 1 + 1 + 1 + 0 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20120111003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1117783936 + ... + 1117783953.

Almost surely, 2^20120111001 is an apocalyptic number.

It is an amenable number.

20120111001 is a deficient number, since it is larger than the sum of its proper divisors (8942271569).

20120111001 is a wasteful number, since it uses less digits than its factorization.

20120111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2235567895 (or 2235567892 counting only the distinct ones).

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

Adding to 20120111001 its reverse (10011102102), we get a palindrome (30131213103).

It can be divided in two parts, 20 and 120111001, that added together give a palindrome (120111021).

The spelling of 20120111001 in words is "twenty billion, one hundred twenty million, one hundred eleven thousand, one".