2157774820 has 12 divisors (see below), whose sum is σ = 4531327164. Its totient is φ = 863109920.

The previous prime is 2157774779. The next prime is 2157774823. The reversal of 2157774820 is 284777512.

It can be written as a sum of positive squares in 2 ways, for example, as 611869696 + 1545905124 = 24736^2 + 39318^2 .

It is not an unprimeable number, because it can be changed into a prime (2157774823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53944351 + ... + 53944390.

It is an arithmetic number, because the mean of its divisors is an integer number (377610597).

Almost surely, 2^2157774820 is an apocalyptic number.

2157774820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2157774820 is an abundant number, since it is smaller than the sum of its proper divisors (2373552344).

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

2157774820 is a wasteful number, since it uses less digits than its factorization.

2157774820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107888750 (or 107888748 counting only the distinct ones).

The product of its (nonzero) digits is 219520, while the sum is 43.

The square root of 2157774820 is about 46451.8548607050. The cubic root of 2157774820 is about 1292.2167721535.

The spelling of 2157774820 in words is "two billion, one hundred fifty-seven million, seven hundred seventy-four thousand, eight hundred twenty".