20453830640 has 80 divisors (see below), whose sum is σ = 49134379008. Its totient is φ = 7913541888.

The previous prime is 20453830633. The next prime is 20453830651. The reversal of 20453830640 is 4603835402.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 20453830640.

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 15 ways as a sum of consecutive naturals, for example, 325457 + ... + 383183.

Almost surely, 2^20453830640 is an apocalyptic number.

20453830640 is a gapful number since it is divisible by the number (20) 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 20453830640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24567189504).

20453830640 is an abundant number, since it is smaller than the sum of its proper divisors (28680548368).

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

20453830640 is a wasteful number, since it uses less digits than its factorization.

20453830640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57886 (or 57880 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 35.

The spelling of 20453830640 in words is "twenty billion, four hundred fifty-three million, eight hundred thirty thousand, six hundred forty".