21010012011 has 8 divisors (see below), whose sum is σ = 31125943760. Its totient is φ = 14006674656.

The previous prime is 21010011989. The next prime is 21010012019. The reversal of 21010012011 is 11021001012.

It is a happy number.

It is not a de Polignac number, because 21010012011 - 2¹⁴ = 21009995627 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 a junction number, because it is equal to n+sod(n) for n = 21010011984 and 21010012002.

It is not an unprimeable number, because it can be changed into a prime (21010012019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 389074270 + ... + 389074323.

It is an arithmetic number, because the mean of its divisors is an integer number (3890742970).

Almost surely, 2^21010012011 is an apocalyptic number.

21010012011 is a deficient number, since it is larger than the sum of its proper divisors (10115931749).

21010012011 is an equidigital number, since it uses as much as digits as its factorization.

21010012011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778148602 (or 778148596 counting only the distinct ones).

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

Adding to 21010012011 its reverse (11021001012), we get a palindrome (32031013023).

It can be divided in two parts, 2101001 and 2011, that added together give a palindrome (2103012).

The spelling of 21010012011 in words is "twenty-one billion, ten million, twelve thousand, eleven".