21708654240 has 288 divisors, whose sum is σ = 85666896000. Its totient is φ = 4580222976.

The previous prime is 21708654151. The next prime is 21708654241. The reversal of 21708654240 is 4245680712.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (21708654241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 270261 + ... + 341259.

It is an arithmetic number, because the mean of its divisors is an integer number (297454500).

Almost surely, 2^21708654240 is an apocalyptic number.

21708654240 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 21708654240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42833448000).

21708654240 is an abundant number, since it is smaller than the sum of its proper divisors (63958241760).

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

21708654240 is a wasteful number, since it uses less digits than its factorization.

21708654240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71044 (or 71029 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 39.

The spelling of 21708654240 in words is "twenty-one billion, seven hundred eight million, six hundred fifty-four thousand, two hundred forty".