2164561012251 has 24 divisors (see below), whose sum is σ = 3444593958000. Its totient is φ = 1298866488000.

The previous prime is 2164561012249. The next prime is 2164561012259. The reversal of 2164561012251 is 1522101654612.

2164561012251 is a `hidden beast` number, since 2 + 1 + 6 + 4 + 5 + 610 + 12 + 25 + 1 = 666.

It is not a de Polignac number, because 2164561012251 - 2¹ = 2164561012249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2164561012259) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 108228876 + ... + 108248873.

It is an arithmetic number, because the mean of its divisors is an integer number (143524748250).

Almost surely, 2^{2164561012251} is an apocalyptic number.

2164561012251 is a deficient number, since it is larger than the sum of its proper divisors (1280032945749).

2164561012251 is a wasteful number, since it uses less digits than its factorization.

2164561012251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216477867 (or 216477864 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

Adding to 2164561012251 its reverse (1522101654612), we get a palindrome (3686662666863).

The spelling of 2164561012251 in words is "two trillion, one hundred sixty-four billion, five hundred sixty-one million, twelve thousand, two hundred fifty-one".