21657230240 has 96 divisors (see below), whose sum is σ = 54459869184. Its totient is φ = 8110428160.

The previous prime is 21657230233. The next prime is 21657230269. The reversal of 21657230240 is 4203275612.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 21657230197 and 21657230206.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 498677 + ... + 540363.

It is an arithmetic number, because the mean of its divisors is an integer number (567290304).

Almost surely, 2^21657230240 is an apocalyptic number.

21657230240 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 21657230240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27229934592).

21657230240 is an abundant number, since it is smaller than the sum of its proper divisors (32802638944).

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

21657230240 is a wasteful number, since it uses less digits than its factorization.

21657230240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41910 (or 41902 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 32.

The spelling of 21657230240 in words is "twenty-one billion, six hundred fifty-seven million, two hundred thirty thousand, two hundred forty".