21959949648 has 320 divisors, whose sum is σ = 75742152192. Its totient is φ = 5317263360.

The previous prime is 21959949569. The next prime is 21959949653. The reversal of 21959949648 is 84694995912.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 3040890 + ... + 3048102.

Almost surely, 2^21959949648 is an apocalyptic number.

21959949648 is a gapful number since it is divisible by the number (28) 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 21959949648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37871076096).

21959949648 is an abundant number, since it is smaller than the sum of its proper divisors (53782202544).

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

21959949648 is a wasteful number, since it uses less digits than its factorization.

21959949648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7302 (or 7296 counting only the distinct ones).

The product of its digits is 50388480, while the sum is 66.

The spelling of 21959949648 in words is "twenty-one billion, nine hundred fifty-nine million, nine hundred forty-nine thousand, six hundred forty-eight".