2121451784 has 32 divisors (see below), whose sum is σ = 4156859520. Its totient is φ = 1014006336.

The previous prime is 2121451781. The next prime is 2121451817. The reversal of 2121451784 is 4871541212.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (2121451781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49439 + ... + 81774.

It is an arithmetic number, because the mean of its divisors is an integer number (129901860).

Almost surely, 2^2121451784 is an apocalyptic number.

It is an amenable number.

2121451784 is a deficient number, since it is larger than the sum of its proper divisors (2035407736).

2121451784 is a wasteful number, since it uses less digits than its factorization.

2121451784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131309 (or 131305 counting only the distinct ones).

The product of its digits is 17920, while the sum is 35.

The square root of 2121451784 is about 46059.2204015656. The cubic root of 2121451784 is about 1284.9248310029.

Adding to 2121451784 its reverse (4871541212), we get a palindrome (6992992996).

The spelling of 2121451784 in words is "two billion, one hundred twenty-one million, four hundred fifty-one thousand, seven hundred eighty-four".