20111201001 has 24 divisors (see below), whose sum is σ = 29945677320. Its totient is φ = 12996550656.

The previous prime is 20111200987. The next prime is 20111201009. The reversal of 20111201001 is 10010211102.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 8164929600 + 11946271401 = 90360^2 + 109299^2 .

It is not a de Polignac number, because 20111201001 - 2⁵ = 20111200969 is a prime.

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 (20111201009) 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, 22680 + ... + 201833.

It is an arithmetic number, because the mean of its divisors is an integer number (1247736555).

Almost surely, 2^20111201001 is an apocalyptic number.

It is an amenable number.

20111201001 is a deficient number, since it is larger than the sum of its proper divisors (9834476319).

20111201001 is a wasteful number, since it uses less digits than its factorization.

20111201001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224825 (or 224822 counting only the distinct ones).

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

Adding to 20111201001 its reverse (10010211102), we get a palindrome (30121412103).

The spelling of 20111201001 in words is "twenty billion, one hundred eleven million, two hundred one thousand, one".