2121440220 has 60 divisors (see below), whose sum is σ = 6655041624. Its totient is φ = 565716960.

The previous prime is 2121440179. The next prime is 2121440227. The reversal of 2121440220 is 220441212.

2121440220 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 440 + 220 = 666.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 2121440193 and 2121440202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121440227) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 653146 + ... + 656385.

Almost surely, 2^2121440220 is an apocalyptic number.

2121440220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121440220 is an abundant number, since it is smaller than the sum of its proper divisors (4533601404).

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

2121440220 is a wasteful number, since it uses less digits than its factorization.

2121440220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1309552 (or 1309541 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 2121440220 is about 46059.0948673549. The cubic root of 2121440220 is about 1284.9224962970.

Adding to 2121440220 its reverse (220441212), we get a palindrome (2341881432).

The spelling of 2121440220 in words is "two billion, one hundred twenty-one million, four hundred forty thousand, two hundred twenty".