20919669408 has 288 divisors, whose sum is σ = 68572707840. Its totient is φ = 5982958080.

The previous prime is 20919669383. The next prime is 20919669439. The reversal of 20919669408 is 80496691902.

20919669408 is a `hidden beast` number, since 2 + 0 + 91 + 96 + 69 + 408 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×20919669408² (a number of 21 digits) contains 22 as substring.

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 47 ways as a sum of consecutive naturals, for example, 22089991 + ... + 22090937.

It is an arithmetic number, because the mean of its divisors is an integer number (238099680).

Almost surely, 2^20919669408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20919669408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34286353920).

20919669408 is an abundant number, since it is smaller than the sum of its proper divisors (47653038432).

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

20919669408 is a wasteful number, since it uses less digits than its factorization.

20919669408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360 (or 1349 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 54.

The spelling of 20919669408 in words is "twenty billion, nine hundred nineteen million, six hundred sixty-nine thousand, four hundred eight".