20421131411021 has 16 divisors (see below), whose sum is σ = 22467509606400. Its totient is φ = 18406593938880.

The previous prime is 20421131410963. The next prime is 20421131411123. The reversal of 20421131411021 is 12011413112402.

It is a cyclic number.

It is not a de Polignac number, because 20421131411021 - 2¹⁰ = 20421131409997 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 (20421131411921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2554526 + ... + 6882431.

It is an arithmetic number, because the mean of its divisors is an integer number (1404219350400).

Almost surely, 2^{20421131411021} is an apocalyptic number.

It is an amenable number.

20421131411021 is a deficient number, since it is larger than the sum of its proper divisors (2046378195379).

20421131411021 is a wasteful number, since it uses less digits than its factorization.

20421131411021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9438644.

The product of its (nonzero) digits is 384, while the sum is 23.

Adding to 20421131411021 its reverse (12011413112402), we get a palindrome (32432544523423).

The spelling of 20421131411021 in words is "twenty trillion, four hundred twenty-one billion, one hundred thirty-one million, four hundred eleven thousand, twenty-one".