21043112040 has 256 divisors, whose sum is σ = 74482675200. Its totient is φ = 5266280448.

The previous prime is 21043112039. The next prime is 21043112063. The reversal of 21043112040 is 4021134012.

21043112040 is a `hidden beast` number, since 210 + 431 + 1 + 20 + 4 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7287477 + ... + 7290363.

It is an arithmetic number, because the mean of its divisors is an integer number (290947950).

Almost surely, 2^21043112040 is an apocalyptic number.

21043112040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21043112040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37241337600).

21043112040 is an abundant number, since it is smaller than the sum of its proper divisors (53439563160).

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

21043112040 is a wasteful number, since it uses less digits than its factorization.

21043112040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3321 (or 3311 counting only the distinct ones).

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

Adding to 21043112040 its reverse (4021134012), we get a palindrome (25064246052).

The spelling of 21043112040 in words is "twenty-one billion, forty-three million, one hundred twelve thousand, forty".