2121603621021 has 24 divisors (see below), whose sum is σ = 3164002243584. Its totient is φ = 1369039371840.

The previous prime is 2121603620971. The next prime is 2121603621061. The reversal of 2121603621021 is 1201263061212.

2121603621021 is a `hidden beast` number, since 2 + 1 + 2 + 16 + 0 + 3 + 621 + 0 + 21 = 666.

It is not a de Polignac number, because 2121603621021 - 2¹⁷ = 2121603489949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121603621061) 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, 22589371 + ... + 22683096.

It is an arithmetic number, because the mean of its divisors is an integer number (131833426816).

Almost surely, 2^{2121603621021} is an apocalyptic number.

It is an amenable number.

2121603621021 is a deficient number, since it is larger than the sum of its proper divisors (1042398622563).

2121603621021 is a wasteful number, since it uses less digits than its factorization.

2121603621021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45272641 (or 45272638 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

Adding to 2121603621021 its reverse (1201263061212), we get a palindrome (3322866682233).

The spelling of 2121603621021 in words is "two trillion, one hundred twenty-one billion, six hundred three million, six hundred twenty-one thousand, twenty-one".