20545566655320 has 1280 divisors, whose sum is σ = 81746454499200. Its totient is φ = 4588382453760.

The previous prime is 20545566655241. The next prime is 20545566655351. The reversal of 20545566655320 is 2355666554502.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 30528330504 + ... + 30528331176.

Almost surely, 2^{20545566655320} is an apocalyptic number.

20545566655320 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 20545566655320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40873227249600).

20545566655320 is an abundant number, since it is smaller than the sum of its proper divisors (61200887843880).

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

20545566655320 is a wasteful number, since it uses less digits than its factorization.

20545566655320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 975 (or 944 counting only the distinct ones).

The product of its (nonzero) digits is 32400000, while the sum is 54.

The spelling of 20545566655320 in words is "twenty trillion, five hundred forty-five billion, five hundred sixty-six million, six hundred fifty-five thousand, three hundred twenty".