2161771567 has 4 divisors (see below), whose sum is σ = 2161917520. Its totient is φ = 2161625616.

The previous prime is 2161771559. The next prime is 2161771571. The reversal of 2161771567 is 7651771612.

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

It is a cyclic number.

It is not a de Polignac number, because 2161771567 - 2³ = 2161771559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161771517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47883 + ... + 81340.

It is an arithmetic number, because the mean of its divisors is an integer number (540479380).

Almost surely, 2^2161771567 is an apocalyptic number.

2161771567 is a deficient number, since it is larger than the sum of its proper divisors (145953).

2161771567 is a wasteful number, since it uses less digits than its factorization.

2161771567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145952.

The product of its digits is 123480, while the sum is 43.

The square root of 2161771567 is about 46494.8552745355. The cubic root of 2161771567 is about 1293.0141179470.

The spelling of 2161771567 in words is "two billion, one hundred sixty-one million, seven hundred seventy-one thousand, five hundred sixty-seven".