2121605000 has 80 divisors (see below), whose sum is σ = 4996962960. Its totient is φ = 844200000.

The previous prime is 2121604987. The next prime is 2121605023. The reversal of 2121605000 is 5061212.

It is a self number, because there is not a number n which added to its sum of digits gives 2121605000.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1053995 + ... + 1056005.

It is an arithmetic number, because the mean of its divisors is an integer number (62462037).

Almost surely, 2^2121605000 is an apocalyptic number.

2121605000 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 2121605000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2498481480).

2121605000 is an abundant number, since it is smaller than the sum of its proper divisors (2875357960).

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

2121605000 is a wasteful number, since it uses less digits than its factorization.

2121605000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2248 (or 2229 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 2121605000 is about 46060.8836215720. The cubic root of 2121605000 is about 1284.9557636414.

Adding to 2121605000 its reverse (5061212), we get a palindrome (2126666212).

The spelling of 2121605000 in words is "two billion, one hundred twenty-one million, six hundred five thousand".