21002124012 has 24 divisors (see below), whose sum is σ = 51584164800. Its totient is φ = 6632249616.

The previous prime is 21002123971. The next prime is 21002124029. The reversal of 21002124012 is 21042120012.

It is a super-2 number, since 2×21002124012² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002123982 and 21002124000.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46057062 + ... + 46057517.

It is an arithmetic number, because the mean of its divisors is an integer number (2149340200).

Almost surely, 2^21002124012 is an apocalyptic number.

It is an amenable number.

21002124012 is an abundant number, since it is smaller than the sum of its proper divisors (30582040788).

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

21002124012 is a wasteful number, since it uses less digits than its factorization.

21002124012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92114605 (or 92114603 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21002124012 its reverse (21042120012), we get a palindrome (42044244024).

The spelling of 21002124012 in words is "twenty-one billion, two million, one hundred twenty-four thousand, twelve".