20203657656 has 128 divisors (see below), whose sum is σ = 63434112000. Its totient is φ = 5328408960.

The previous prime is 20203657601. The next prime is 20203657673. The reversal of 20203657656 is 65675630202.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12621 + ... + 201411.

It is an arithmetic number, because the mean of its divisors is an integer number (495579000).

Almost surely, 2^20203657656 is an apocalyptic number.

20203657656 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 20203657656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31717056000).

20203657656 is an abundant number, since it is smaller than the sum of its proper divisors (43230454344).

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

20203657656 is a wasteful number, since it uses less digits than its factorization.

20203657656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188834 (or 188816 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 42.

The spelling of 20203657656 in words is "twenty billion, two hundred three million, six hundred fifty-seven thousand, six hundred fifty-six".