2188461961 has 27 divisors (see below), whose sum is σ = 2625474663. Its totient is φ = 1818845280.

The previous prime is 2188461953. The next prime is 2188462007. The reversal of 2188461961 is 1691648812.

The square root of 2188461961 is 46781.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 105452361 + 2083009600 = 10269^2 + 45640^2 .

It is not a de Polignac number, because 2188461961 - 2³ = 2188461953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2188461931) 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 26 ways as a sum of consecutive naturals, for example, 13426066 + ... + 13426228.

Almost surely, 2^2188461961 is an apocalyptic number.

2188461961 is the 46781-st square number.

2188461961 is the 23391-st centered octagonal number.

It is an amenable number.

2188461961 is a deficient number, since it is larger than the sum of its proper divisors (437012702).

2188461961 is an frugal number, since it uses more digits than its factorization.

2188461961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422 (or 211 counting only the distinct ones).

The product of its digits is 165888, while the sum is 46.

The cubic root of 2188461961 is about 1298.3137824080.

It can be divided in two parts, 21884 and 61961, that added together give a triangular number (83845 = T₄₀₉).

The spelling of 2188461961 in words is "two billion, one hundred eighty-eight million, four hundred sixty-one thousand, nine hundred sixty-one".