2161244980 has 48 divisors (see below), whose sum is σ = 4711150080. Its totient is φ = 831945600.

The previous prime is 2161244977. The next prime is 2161245001. The reversal of 2161244980 is 894421612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102591 + ... + 121849.

It is an arithmetic number, because the mean of its divisors is an integer number (98148960).

Almost surely, 2^2161244980 is an apocalyptic number.

2161244980 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 2161244980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2355575040).

2161244980 is an abundant number, since it is smaller than the sum of its proper divisors (2549905100).

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

2161244980 is a wasteful number, since it uses less digits than its factorization.

2161244980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19480 (or 19478 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 2161244980 is about 46489.1920772990. The cubic root of 2161244980 is about 1292.9091207727.

The spelling of 2161244980 in words is "two billion, one hundred sixty-one million, two hundred forty-four thousand, nine hundred eighty".