21532122240 has 128 divisors (see below), whose sum is σ = 68683144320. Its totient is φ = 5737758720.

The previous prime is 21532122239. The next prime is 21532122281. The reversal of 21532122240 is 4222123512.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21532122240.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3408685 + ... + 3414995.

It is an arithmetic number, because the mean of its divisors is an integer number (536587065).

Almost surely, 2^21532122240 is an apocalyptic number.

21532122240 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 21532122240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34341572160).

21532122240 is an abundant number, since it is smaller than the sum of its proper divisors (47151022080).

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

21532122240 is a wasteful number, since it uses less digits than its factorization.

21532122240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8110 (or 8098 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 21532122240 its reverse (4222123512), we get a palindrome (25754245752).

The spelling of 21532122240 in words is "twenty-one billion, five hundred thirty-two million, one hundred twenty-two thousand, two hundred forty".