21002020124 has 48 divisors (see below), whose sum is σ = 38382489600. Its totient is φ = 10048237056.

The previous prime is 21002020103. The next prime is 21002020163. The reversal of 21002020124 is 42102020012.

It is a junction number, because it is equal to n+sod(n) for n = 21002020099 and 21002020108.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1522892 + ... + 1536620.

It is an arithmetic number, because the mean of its divisors is an integer number (799635200).

Almost surely, 2^21002020124 is an apocalyptic number.

It is an amenable number.

21002020124 is a deficient number, since it is larger than the sum of its proper divisors (17380469476).

21002020124 is a wasteful number, since it uses less digits than its factorization.

21002020124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13962 (or 13960 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21002020124 its reverse (42102020012), we get a palindrome (63104040136).

The spelling of 21002020124 in words is "twenty-one billion, two million, twenty thousand, one hundred twenty-four".