21432381560 has 64 divisors (see below), whose sum is σ = 49985100000. Its totient is φ = 8260844032.

The previous prime is 21432381547. The next prime is 21432381569. The reversal of 21432381560 is 6518323412.

It is a self number, because there is not a number n which added to its sum of digits gives 21432381560.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432381569) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 572291 + ... + 608589.

Almost surely, 2^21432381560 is an apocalyptic number.

21432381560 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 21432381560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24992550000).

21432381560 is an abundant number, since it is smaller than the sum of its proper divisors (28552718440).

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

21432381560 is a wasteful number, since it uses less digits than its factorization.

21432381560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36848 (or 36844 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

The spelling of 21432381560 in words is "twenty-one billion, four hundred thirty-two million, three hundred eighty-one thousand, five hundred sixty".