21131130240 has 288 divisors, whose sum is σ = 80207618400. Its totient is φ = 5122529280.

The previous prime is 21131130221. The next prime is 21131130259. The reversal of 21131130240 is 4203113112.

21131130240 is a `hidden beast` number, since 2 + 11 + 311 + 302 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (21131130221) and next prime (21131130259).

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 681801 + ... + 712119.

It is an arithmetic number, because the mean of its divisors is an integer number (278498675).

Almost surely, 2^21131130240 is an apocalyptic number.

21131130240 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 21131130240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40103809200).

21131130240 is an abundant number, since it is smaller than the sum of its proper divisors (59076488160).

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

21131130240 is a wasteful number, since it uses less digits than its factorization.

21131130240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30366 (or 30340 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21131130240 its reverse (4203113112), we get a palindrome (25334243352).

The spelling of 21131130240 in words is "twenty-one billion, one hundred thirty-one million, one hundred thirty thousand, two hundred forty".