20155105500 has 192 divisors, whose sum is σ = 59692913280. Its totient is φ = 5283840000.

The previous prime is 20155105447. The next prime is 20155105511. The reversal of 20155105500 is 550155102.

It is a super-2 number, since 2×20155105500² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 26209116 + ... + 26209884.

It is an arithmetic number, because the mean of its divisors is an integer number (310900590).

Almost surely, 2^20155105500 is an apocalyptic number.

20155105500 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 20155105500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29846456640).

20155105500 is an abundant number, since it is smaller than the sum of its proper divisors (39537807780).

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

20155105500 is a wasteful number, since it uses less digits than its factorization.

20155105500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1065 (or 1053 counting only the distinct ones).

The product of its (nonzero) digits is 1250, while the sum is 24.

The spelling of 20155105500 in words is "twenty billion, one hundred fifty-five million, one hundred five thousand, five hundred".