21012442011 has 16 divisors (see below), whose sum is σ = 33959502720. Its totient is φ = 12734813160.

The previous prime is 21012442001. The next prime is 21012442021. The reversal of 21012442011 is 11024421012.

21012442011 is a `hidden beast` number, since 210 + 1 + 2 + 442 + 0 + 11 = 666.

It is an interprime number because it is at equal distance from previous prime (21012442001) and next prime (21012442021).

It is not a de Polignac number, because 21012442011 - 2²² = 21008247707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21012442001) 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, 35374185 + ... + 35374778.

It is an arithmetic number, because the mean of its divisors is an integer number (2122468920).

Almost surely, 2^21012442011 is an apocalyptic number.

21012442011 is a deficient number, since it is larger than the sum of its proper divisors (12947060709).

21012442011 is a wasteful number, since it uses less digits than its factorization.

21012442011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70748983 (or 70748977 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21012442011 its reverse (11024421012), we get a palindrome (32036863023).

The spelling of 21012442011 in words is "twenty-one billion, twelve million, four hundred forty-two thousand, eleven".