21000012110 has 64 divisors (see below), whose sum is σ = 49899525120. Its totient is φ = 6160427520.

The previous prime is 21000012107. The next prime is 21000012113. The reversal of 21000012110 is 1121000012.

It is an interprime number because it is at equal distance from previous prime (21000012107) and next prime (21000012113).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000012113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 789050 + ... + 815229.

It is an arithmetic number, because the mean of its divisors is an integer number (779680080).

Almost surely, 2^21000012110 is an apocalyptic number.

21000012110 is an abundant number, since it is smaller than the sum of its proper divisors (28899513010).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21000012110 is a wasteful number, since it uses less digits than its factorization.

21000012110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1604321.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21000012110 its reverse (1121000012), we get a palindrome (22121012122).

The spelling of 21000012110 in words is "twenty-one billion, twelve thousand, one hundred ten".