2104121210021 has 4 divisors (see below), whose sum is σ = 2105644832844. Its totient is φ = 2102597587200.

The previous prime is 2104121209999. The next prime is 2104121210027. The reversal of 2104121210021 is 1200121214012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 725246404996 + 1378874805025 = 851614^2 + 1174255^2 .

It is a cyclic number.

It is not a de Polignac number, because 2104121210021 - 2¹⁰ = 2104121208997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2104121210027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 761809340 + ... + 761812101.

It is an arithmetic number, because the mean of its divisors is an integer number (526411208211).

Almost surely, 2^{2104121210021} is an apocalyptic number.

It is an amenable number.

2104121210021 is a deficient number, since it is larger than the sum of its proper divisors (1523622823).

2104121210021 is a wasteful number, since it uses less digits than its factorization.

2104121210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1523622822.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2104121210021 its reverse (1200121214012), we get a palindrome (3304242424033).

The spelling of 2104121210021 in words is "two trillion, one hundred four billion, one hundred twenty-one million, two hundred ten thousand, twenty-one".