21120012001 has 16 divisors (see below), whose sum is σ = 24258859200. Its totient is φ = 18184824000.

The previous prime is 21120011987. The next prime is 21120012007. The reversal of 21120012001 is 10021002112.

It is not a de Polignac number, because 21120012001 - 2¹³ = 21120003809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21120012007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 990351 + ... + 1011451.

It is an arithmetic number, because the mean of its divisors is an integer number (1516178700).

Almost surely, 2^21120012001 is an apocalyptic number.

It is an amenable number.

21120012001 is a deficient number, since it is larger than the sum of its proper divisors (3138847199).

21120012001 is a wasteful number, since it uses less digits than its factorization.

21120012001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25920.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21120012001 its reverse (10021002112), we get a palindrome (31141014113).

The spelling of 21120012001 in words is "twenty-one billion, one hundred twenty million, twelve thousand, one".