20121777608500 has 96 divisors (see below), whose sum is σ = 44070544627200. Its totient is φ = 8025902236800.

The previous prime is 20121777608489. The next prime is 20121777608519. The reversal of 20121777608500 is 580677712102.

It is a super-3 number, since 3×20121777608500³ (a number of 41 digits) contains 333 as substring.

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, 1706820606 + ... + 1706832394.

It is an arithmetic number, because the mean of its divisors is an integer number (459068173200).

Almost surely, 2^{20121777608500} is an apocalyptic number.

20121777608500 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 20121777608500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22035272313600).

20121777608500 is an abundant number, since it is smaller than the sum of its proper divisors (23948767018700).

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

20121777608500 is a wasteful number, since it uses less digits than its factorization.

20121777608500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21194 (or 21182 counting only the distinct ones).

The product of its (nonzero) digits is 329280, while the sum is 46.

The spelling of 20121777608500 in words is "twenty trillion, one hundred twenty-one billion, seven hundred seventy-seven million, six hundred eight thousand, five hundred".