21124213020 has 48 divisors (see below), whose sum is σ = 65719775520. Its totient is φ = 5633123328.

The previous prime is 21124213007. The next prime is 21124213079. The reversal of 21124213020 is 2031242112.

It is a happy number.

21124213020 is a `hidden beast` number, since 211 + 2 + 421 + 30 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21124212984 and 21124213002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19558917 + ... + 19559996.

It is an arithmetic number, because the mean of its divisors is an integer number (1369161990).

Almost surely, 2^21124213020 is an apocalyptic number.

21124213020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21124213020 is an abundant number, since it is smaller than the sum of its proper divisors (44595562500).

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

21124213020 is a wasteful number, since it uses less digits than its factorization.

21124213020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39118931 (or 39118923 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21124213020 its reverse (2031242112), we get a palindrome (23155455132).

The spelling of 21124213020 in words is "twenty-one billion, one hundred twenty-four million, two hundred thirteen thousand, twenty".