2165421501000 has 384 divisors, whose sum is σ = 7453186191360. Its totient is φ = 566963712000.

The previous prime is 2165421500987. The next prime is 2165421501011. The reversal of 2165421501000 is 1051245612.

2165421501000 is a `hidden beast` number, since 2 + 1 + 6 + 542 + 15 + 0 + 100 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 110861235 + ... + 110880765.

It is an arithmetic number, because the mean of its divisors is an integer number (19409339040).

Almost surely, 2^{2165421501000} is an apocalyptic number.

2165421501000 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 2165421501000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3726593095680).

2165421501000 is an abundant number, since it is smaller than the sum of its proper divisors (5287764690360).

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

2165421501000 is a wasteful number, since it uses less digits than its factorization.

2165421501000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19782 (or 19765 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

Adding to 2165421501000 its reverse (1051245612), we get a palindrome (2166472746612).

The spelling of 2165421501000 in words is "two trillion, one hundred sixty-five billion, four hundred twenty-one million, five hundred one thousand".