2121641023653 has 6 divisors (see below), whose sum is σ = 3064592589734. Its totient is φ = 1414427349096.

The previous prime is 2121641023609. The next prime is 2121641023679. The reversal of 2121641023653 is 3563201461212.

2121641023653 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 6 + 410 + 236 + 5 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2063425950369 + 58215073284 = 1436463^2 + 241278^2 .

It is not a de Polignac number, because 2121641023653 - 2¹² = 2121641019557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121641028653) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 117868945750 + ... + 117868945767.

Almost surely, 2^{2121641023653} is an apocalyptic number.

It is an amenable number.

2121641023653 is a deficient number, since it is larger than the sum of its proper divisors (942951566081).

2121641023653 is a wasteful number, since it uses less digits than its factorization.

2121641023653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235737891523 (or 235737891520 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

Adding to 2121641023653 its reverse (3563201461212), we get a palindrome (5684842484865).

The spelling of 2121641023653 in words is "two trillion, one hundred twenty-one billion, six hundred forty-one million, twenty-three thousand, six hundred fifty-three".