21001042224 has 30 divisors (see below), whose sum is σ = 58773750516. Its totient is φ = 7000347360.

The previous prime is 21001042219. The next prime is 21001042267. The reversal of 21001042224 is 42224010012.

21001042224 is a `hidden beast` number, since 210 + 0 + 10 + 422 + 24 = 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 = 21001042197 and 21001042206.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 72920142 + ... + 72920429.

Almost surely, 2^21001042224 is an apocalyptic number.

21001042224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21001042224 is an abundant number, since it is smaller than the sum of its proper divisors (37772708292).

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

21001042224 is a wasteful number, since it uses less digits than its factorization.

21001042224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145840585 (or 145840576 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21001042224 its reverse (42224010012), we get a palindrome (63225052236).

The spelling of 21001042224 in words is "twenty-one billion, one million, forty-two thousand, two hundred twenty-four".