21405513132 has 108 divisors (see below), whose sum is σ = 56724488184. Its totient is φ = 6805497600.

The previous prime is 21405513079. The next prime is 21405513137. The reversal of 21405513132 is 23131550412.

21405513132 is a `hidden beast` number, since 2 + 14 + 0 + 5 + 513 + 132 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21405513096 and 21405513105.

It is not an unprimeable number, because it can be changed into a prime (21405513137) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 7635243 + ... + 7638045.

Almost surely, 2^21405513132 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21405513132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28362244092).

21405513132 is an abundant number, since it is smaller than the sum of its proper divisors (35318975052).

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

21405513132 is a wasteful number, since it uses less digits than its factorization.

21405513132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3260 (or 3232 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The spelling of 21405513132 in words is "twenty-one billion, four hundred five million, five hundred thirteen thousand, one hundred thirty-two".