2171257780 has 12 divisors (see below), whose sum is σ = 4559641380. Its totient is φ = 868503104.

The previous prime is 2171257741. The next prime is 2171257831. The reversal of 2171257780 is 877521712.

It can be written as a sum of positive squares in 2 ways, for example, as 598976676 + 1572281104 = 24474^2 + 39652^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54281425 + ... + 54281464.

It is an arithmetic number, because the mean of its divisors is an integer number (379970115).

Almost surely, 2^2171257780 is an apocalyptic number.

2171257780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2171257780 is an abundant number, since it is smaller than the sum of its proper divisors (2388383600).

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

2171257780 is a wasteful number, since it uses less digits than its factorization.

2171257780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108562898 (or 108562896 counting only the distinct ones).

The product of its (nonzero) digits is 54880, while the sum is 40.

The square root of 2171257780 is about 46596.7571833062. The cubic root of 2171257780 is about 1294.9026784940.

The spelling of 2171257780 in words is "two billion, one hundred seventy-one million, two hundred fifty-seven thousand, seven hundred eighty".