20749664208 has 160 divisors (see below), whose sum is σ = 66654789376. Its totient is φ = 5415911424.

The previous prime is 20749664207. The next prime is 20749664219. The reversal of 20749664208 is 80246694702.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20749664207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 399210 + ... + 448182.

Almost surely, 2^20749664208 is an apocalyptic number.

20749664208 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 20749664208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33327394688).

20749664208 is an abundant number, since it is smaller than the sum of its proper divisors (45905125168).

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

20749664208 is a wasteful number, since it uses less digits than its factorization.

20749664208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49101 (or 49095 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 48.

The spelling of 20749664208 in words is "twenty billion, seven hundred forty-nine million, six hundred sixty-four thousand, two hundred eight".