20628535680 has 320 divisors, whose sum is σ = 73918706400. Its totient is φ = 5482266624.

The previous prime is 20628535643. The next prime is 20628535687. The reversal of 20628535680 is 8653582602.

20628535680 is a `hidden beast` number, since 2 + 0 + 6 + 2 + 85 + 3 + 568 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20628535687) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 22446261 + ... + 22447179.

Almost surely, 2^20628535680 is an apocalyptic number.

20628535680 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 20628535680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36959353200).

20628535680 is an abundant number, since it is smaller than the sum of its proper divisors (53290170720).

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

20628535680 is an equidigital number, since it uses as much as digits as its factorization.

20628535680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1383 (or 1362 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 20628535680 in words is "twenty billion, six hundred twenty-eight million, five hundred thirty-five thousand, six hundred eighty".