21004410042 has 96 divisors (see below), whose sum is σ = 56779467264. Its totient is φ = 5451818400.

The previous prime is 21004410041. The next prime is 21004410043. The reversal of 21004410042 is 24001440012.

21004410042 is a `hidden beast` number, since 210 + 0 + 4 + 410 + 0 + 42 = 666.

It is an interprime number because it is at equal distance from previous prime (21004410041) and next prime (21004410043).

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 = 21004409997 and 21004410024.

It is not an unprimeable number, because it can be changed into a prime (21004410041) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2305917 + ... + 2315007.

It is an arithmetic number, because the mean of its divisors is an integer number (591452784).

Almost surely, 2^21004410042 is an apocalyptic number.

21004410042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21004410042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28389733632).

21004410042 is an abundant number, since it is smaller than the sum of its proper divisors (35775057222).

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

21004410042 is a wasteful number, since it uses less digits than its factorization.

21004410042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10784 (or 10781 counting only the distinct ones).

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

Adding to 21004410042 its reverse (24001440012), we get a palindrome (45005850054).

The spelling of 21004410042 in words is "twenty-one billion, four million, four hundred ten thousand, forty-two".