21161065570 has 8 divisors (see below), whose sum is σ = 38089918044. Its totient is φ = 8464426224.

The previous prime is 21161065561. The next prime is 21161065573. The reversal of 21161065570 is 7556016112.

It can be written as a sum of positive squares in 2 ways, for example, as 20924490409 + 236575161 = 144653^2 + 15381^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21161065573) 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, 1058053269 + ... + 1058053288.

Almost surely, 2^21161065570 is an apocalyptic number.

21161065570 is a deficient number, since it is larger than the sum of its proper divisors (16928852474).

21161065570 is a wasteful number, since it uses less digits than its factorization.

21161065570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2116106564.

The product of its (nonzero) digits is 12600, while the sum is 34.

The spelling of 21161065570 in words is "twenty-one billion, one hundred sixty-one million, sixty-five thousand, five hundred seventy".