21442121020521 has 12 divisors (see below), whose sum is σ = 32318559219648. Its totient is φ = 13673236592664.

The previous prime is 21442121020511. The next prime is 21442121020547. The reversal of 21442121020521 is 12502012124412.

21442121020521 is a `hidden beast` number, since 2 + 1 + 4 + 421 + 2 + 10 + 205 + 21 = 666.

It is not a de Polignac number, because 21442121020521 - 2⁹ = 21442121020009 is a prime.

It is a super-2 number, since 2×21442121020521² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21442121020511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51792562645 + ... + 51792563058.

It is an arithmetic number, because the mean of its divisors is an integer number (2693213268304).

Almost surely, 2^{21442121020521} is an apocalyptic number.

It is an amenable number.

21442121020521 is a deficient number, since it is larger than the sum of its proper divisors (10876438199127).

21442121020521 is a wasteful number, since it uses less digits than its factorization.

21442121020521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103585125732 (or 103585125729 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

Adding to 21442121020521 its reverse (12502012124412), we get a palindrome (33944133144933).

The spelling of 21442121020521 in words is "twenty-one trillion, four hundred forty-two billion, one hundred twenty-one million, twenty thousand, five hundred twenty-one".