20618453856 has 192 divisors, whose sum is σ = 72669574656. Its totient is φ = 4943462400.

The previous prime is 20618453851. The next prime is 20618453857. The reversal of 20618453856 is 65835481602.

It is a happy number.

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 (20618453851) 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, 11185 + ... + 203376.

It is an arithmetic number, because the mean of its divisors is an integer number (378487368).

Almost surely, 2^20618453856 is an apocalyptic number.

20618453856 is a gapful number since it is divisible by the number (26) 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 20618453856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36334787328).

20618453856 is an abundant number, since it is smaller than the sum of its proper divisors (52051120800).

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

20618453856 is a wasteful number, since it uses less digits than its factorization.

20618453856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214605 (or 214597 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 48.

It can be divided in two parts, 20618 and 453856, that added together give a palindrome (474474).

The spelling of 20618453856 in words is "twenty billion, six hundred eighteen million, four hundred fifty-three thousand, eight hundred fifty-six".