2172027780 has 144 divisors (see below), whose sum is σ = 7512798384. Its totient is φ = 503193600.

The previous prime is 2172027757. The next prime is 2172027827. The reversal of 2172027780 is 877202712.

It can be written as a sum of positive squares in 8 ways, for example, as 356756544 + 1815271236 = 18888^2 + 42606^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12480 + ... + 67080.

It is an arithmetic number, because the mean of its divisors is an integer number (52172211).

Almost surely, 2^2172027780 is an apocalyptic number.

2172027780 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 2172027780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3756399192).

2172027780 is an abundant number, since it is smaller than the sum of its proper divisors (5340770604).

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

2172027780 is a wasteful number, since it uses less digits than its factorization.

2172027780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54646 (or 54641 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 2172027780 is about 46605.0188284481. The cubic root of 2172027780 is about 1295.0557322109.

The spelling of 2172027780 in words is "two billion, one hundred seventy-two million, twenty-seven thousand, seven hundred eighty".