21536234460 has 216 divisors, whose sum is σ = 73816221024. Its totient is φ = 5070574080.

The previous prime is 21536234453. The next prime is 21536234479. The reversal of 21536234460 is 6443263512.

21536234460 is a `hidden beast` number, since 2 + 1 + 536 + 23 + 44 + 60 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 684270 + ... + 715050.

It is an arithmetic number, because the mean of its divisors is an integer number (341741764).

Almost surely, 2^21536234460 is an apocalyptic number.

21536234460 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 21536234460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36908110512).

21536234460 is an abundant number, since it is smaller than the sum of its proper divisors (52279986564).

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

21536234460 is a wasteful number, since it uses less digits than its factorization.

21536234460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30845 (or 30827 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

Adding to 21536234460 its reverse (6443263512), we get a palindrome (27979497972).

The spelling of 21536234460 in words is "twenty-one billion, five hundred thirty-six million, two hundred thirty-four thousand, four hundred sixty".