20456636140 has 96 divisors (see below), whose sum is σ = 45682560000. Its totient is φ = 7673087232.

The previous prime is 20456636117. The next prime is 20456636147. The reversal of 20456636140 is 4163665402.

It is a self number, because there is not a number n which added to its sum of digits gives 20456636140.

It is not an unprimeable number, because it can be changed into a prime (20456636147) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24855769 + ... + 24856591.

It is an arithmetic number, because the mean of its divisors is an integer number (475860000).

Almost surely, 2^20456636140 is an apocalyptic number.

20456636140 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 20456636140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22841280000).

20456636140 is an abundant number, since it is smaller than the sum of its proper divisors (25225923860).

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

20456636140 is a wasteful number, since it uses less digits than its factorization.

20456636140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439 (or 1437 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 37.

The spelling of 20456636140 in words is "twenty billion, four hundred fifty-six million, six hundred thirty-six thousand, one hundred forty".