20213685408 has 144 divisors (see below), whose sum is σ = 63715486464. Its totient is φ = 5588997120.

The previous prime is 20213685347. The next prime is 20213685409. The reversal of 20213685408 is 80458631202.

It is not an unprimeable number, because it can be changed into a prime (20213685409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76516 + ... + 215132.

It is an arithmetic number, because the mean of its divisors is an integer number (442468656).

Almost surely, 2^20213685408 is an apocalyptic number.

20213685408 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 20213685408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31857743232).

20213685408 is an abundant number, since it is smaller than the sum of its proper divisors (43501801056).

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

20213685408 is a wasteful number, since it uses less digits than its factorization.

20213685408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138675 (or 138660 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 39.

The spelling of 20213685408 in words is "twenty billion, two hundred thirteen million, six hundred eighty-five thousand, four hundred eight".