20211421021 has 8 divisors (see below), whose sum is σ = 22561586784. Its totient is φ = 17946715920.

The previous prime is 20211421007. The next prime is 20211421039. The reversal of 20211421021 is 12012411202.

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 20211421021 - 2¹¹ = 20211418973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211420986 and 20211421004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211421001) 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, 21364666 + ... + 21365611.

It is an arithmetic number, because the mean of its divisors is an integer number (2820198348).

Almost surely, 2^20211421021 is an apocalyptic number.

It is an amenable number.

20211421021 is a deficient number, since it is larger than the sum of its proper divisors (2350165763).

20211421021 is a wasteful number, since it uses less digits than its factorization.

20211421021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42730331.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20211421021 its reverse (12012411202), we get a palindrome (32223832223).

The spelling of 20211421021 in words is "twenty billion, two hundred eleven million, four hundred twenty-one thousand, twenty-one".