2161850749 has 4 divisors (see below), whose sum is σ = 2167242300. Its totient is φ = 2156459200.

The previous prime is 2161850711. The next prime is 2161850767. The reversal of 2161850749 is 9470581612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1566734724 + 595116025 = 39582^2 + 24395^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161850749 - 2¹¹ = 2161848701 is a prime.

It is a super-2 number, since 2×2161850749² = 9347197321903722002, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161857749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2695174 + ... + 2695975.

It is an arithmetic number, because the mean of its divisors is an integer number (541810575).

Almost surely, 2^2161850749 is an apocalyptic number.

It is an amenable number.

2161850749 is a deficient number, since it is larger than the sum of its proper divisors (5391551).

2161850749 is an equidigital number, since it uses as much as digits as its factorization.

2161850749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5391550.

The product of its (nonzero) digits is 120960, while the sum is 43.

The square root of 2161850749 is about 46495.7067803039. The cubic root of 2161850749 is about 1293.0299047205.

The spelling of 2161850749 in words is "two billion, one hundred sixty-one million, eight hundred fifty thousand, seven hundred forty-nine".