2121400123021 has 8 divisors (see below), whose sum is σ = 2128121184384. Its totient is φ = 2114686180800.

The previous prime is 2121400122977. The next prime is 2121400123043. The reversal of 2121400123021 is 1203210041212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2121400123021 - 2¹⁵ = 2121400090253 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2121400123021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121400123421) 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, 1182555 + ... + 2375128.

It is an arithmetic number, because the mean of its divisors is an integer number (266015148048).

Almost surely, 2^{2121400123021} is an apocalyptic number.

It is an amenable number.

2121400123021 is a deficient number, since it is larger than the sum of its proper divisors (6721061363).

2121400123021 is a wasteful number, since it uses less digits than its factorization.

2121400123021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3559571.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 2121400123021 its reverse (1203210041212), we get a palindrome (3324610164233).

The spelling of 2121400123021 in words is "two trillion, one hundred twenty-one billion, four hundred million, one hundred twenty-three thousand, twenty-one".