2161271520 has 144 divisors (see below), whose sum is σ = 7390695312. Its totient is φ = 575139840.

The previous prime is 2161271513. The next prime is 2161271537. The reversal of 2161271520 is 251721612.

2161271520 is a `hidden beast` number, since 2 + 16 + 127 + 1 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×2161271520² = 9342189166326220800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 852655 + ... + 855185.

It is an arithmetic number, because the mean of its divisors is an integer number (51324273).

Almost surely, 2^2161271520 is an apocalyptic number.

2161271520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2161271520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3695347656).

2161271520 is an abundant number, since it is smaller than the sum of its proper divisors (5229423792).

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

2161271520 is a wasteful number, since it uses less digits than its factorization.

2161271520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3145 (or 3134 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 2161271520 is about 46489.4775191118. The cubic root of 2161271520 is about 1292.9144130414.

The spelling of 2161271520 in words is "two billion, one hundred sixty-one million, two hundred seventy-one thousand, five hundred twenty".