2166157764 has 27 divisors (see below), whose sum is σ = 5476271437. Its totient is φ = 721959504.

The previous prime is 2166157729. The next prime is 2166157783. The reversal of 2166157764 is 4677516612.

The square root of 2166157764 is 46542.

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

2166157764 is a `hidden beast` number, since 2 + 16 + 6 + 1 + 577 + 64 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1781684100 + 384473664 = 42210^2 + 19608^2 .

It is a Duffinian number.

It is an unprimeable number.

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 8 ways as a sum of consecutive naturals, for example, 275374 + ... + 283130.

Almost surely, 2^2166157764 is an apocalyptic number.

2166157764 is the 46542-nd square number.

It is an amenable number.

2166157764 is an abundant number, since it is smaller than the sum of its proper divisors (3310113673).

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

2166157764 is an frugal number, since it uses more digits than its factorization.

2166157764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15524 (or 7762 counting only the distinct ones).

The product of its digits is 423360, while the sum is 45.

The cubic root of 2166157764 is about 1293.8880282336. Note that the first 3 decimals are identical.

The spelling of 2166157764 in words is "two billion, one hundred sixty-six million, one hundred fifty-seven thousand, seven hundred sixty-four".