21688654280 has 64 divisors (see below), whose sum is σ = 51390158400. Its totient is φ = 8215292160.

The previous prime is 21688654243. The next prime is 21688654283. The reversal of 21688654280 is 8245688612.

It is not an unprimeable number, because it can be changed into a prime (21688654283) by changing a digit.

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, 2321699 + ... + 2331021.

It is an arithmetic number, because the mean of its divisors is an integer number (802971225).

Almost surely, 2^21688654280 is an apocalyptic number.

21688654280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21688654280 is an abundant number, since it is smaller than the sum of its proper divisors (29701504120).

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

21688654280 is a wasteful number, since it uses less digits than its factorization.

21688654280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12414 (or 12410 counting only the distinct ones).

The product of its (nonzero) digits is 1474560, while the sum is 50.

The spelling of 21688654280 in words is "twenty-one billion, six hundred eighty-eight million, six hundred fifty-four thousand, two hundred eighty".