2161980 has 36 divisors (see below), whose sum is σ = 6558552. Its totient is φ = 576480.

The previous prime is 2161967. The next prime is 2161987. The reversal of 2161980 is 891612.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161987) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5826 + ... + 6185.

It is an arithmetic number, because the mean of its divisors is an integer number (182182).

2^2161980 is an apocalyptic number.

2161980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2161980 is an abundant number, since it is smaller than the sum of its proper divisors (4396572).

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

2161980 is a wasteful number, since it uses less digits than its factorization.

2161980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12026 (or 12021 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 2161980 is about 1470.3673010510. The cubic root of 2161980 is about 129.3055673085.

It can be divided in two parts, 21 and 61980, that added together give a square (62001 = 249²).

The spelling of 2161980 in words is "two million, one hundred sixty-one thousand, nine hundred eighty".