2117785140 has 72 divisors (see below), whose sum is σ = 6457338888. Its totient is φ = 561807360.

The previous prime is 2117785133. The next prime is 2117785147. The reversal of 2117785140 is 415877112.

It is an interprime number because it is at equal distance from previous prime (2117785133) and next prime (2117785147).

It can be written as a sum of positive squares in 4 ways, for example, as 64064016 + 2053721124 = 8004^2 + 45318^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2117785095 and 2117785104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2117785147) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4260 + ... + 65220.

Almost surely, 2^2117785140 is an apocalyptic number.

2117785140 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 2117785140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3228669444).

2117785140 is an abundant number, since it is smaller than the sum of its proper divisors (4339553748).

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

2117785140 is a wasteful number, since it uses less digits than its factorization.

2117785140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61169 (or 61164 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 36.

The square root of 2117785140 is about 46019.3996049492. The cubic root of 2117785140 is about 1284.1841308708.

The spelling of 2117785140 in words is "two billion, one hundred seventeen million, seven hundred eighty-five thousand, one hundred forty".