21400302240 has 144 divisors (see below), whose sum is σ = 73195563168. Its totient is φ = 5693695488.

The previous prime is 21400302173. The next prime is 21400302241. The reversal of 21400302240 is 4220300412.

21400302240 is a `hidden beast` number, since 21 + 400 + 3 + 0 + 2 + 240 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is not an unprimeable number, because it can be changed into a prime (21400302241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 621147 + ... + 654693.

It is an arithmetic number, because the mean of its divisors is an integer number (508302522).

Almost surely, 2^21400302240 is an apocalyptic number.

21400302240 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 21400302240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36597781584).

21400302240 is an abundant number, since it is smaller than the sum of its proper divisors (51795260928).

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

21400302240 is a wasteful number, since it uses less digits than its factorization.

21400302240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34011 (or 34000 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21400302240 its reverse (4220300412), we get a palindrome (25620602652).

The spelling of 21400302240 in words is "twenty-one billion, four hundred million, three hundred two thousand, two hundred forty".