21225018240 has 384 divisors, whose sum is σ = 77126100480. Its totient is φ = 5368197120.

The previous prime is 21225018233. The next prime is 21225018257. The reversal of 21225018240 is 4281052212.

21225018240 is a `hidden beast` number, since 21 + 22 + 501 + 82 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17354269 + ... + 17355491.

It is an arithmetic number, because the mean of its divisors is an integer number (200849220).

Almost surely, 2^21225018240 is an apocalyptic number.

21225018240 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 21225018240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38563050240).

21225018240 is an abundant number, since it is smaller than the sum of its proper divisors (55901082240).

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

21225018240 is a wasteful number, since it uses less digits than its factorization.

21225018240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1402 (or 1387 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The spelling of 21225018240 in words is "twenty-one billion, two hundred twenty-five million, eighteen thousand, two hundred forty".