20123211421 has 4 divisors (see below), whose sum is σ = 20301293052. Its totient is φ = 19945129792.

The previous prime is 20123211419. The next prime is 20123211439. The reversal of 20123211421 is 12411232102.

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 5915763396 + 14207448025 = 76914^2 + 119195^2 .

It is a cyclic number.

It is not a de Polignac number, because 20123211421 - 2¹ = 20123211419 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 (20123211401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89040646 + ... + 89040871.

It is an arithmetic number, because the mean of its divisors is an integer number (5075323263).

Almost surely, 2^20123211421 is an apocalyptic number.

It is an amenable number.

20123211421 is a deficient number, since it is larger than the sum of its proper divisors (178081631).

20123211421 is a wasteful number, since it uses less digits than its factorization.

20123211421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178081630.

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

Adding to 20123211421 its reverse (12411232102), we get a palindrome (32534443523).

The spelling of 20123211421 in words is "twenty billion, one hundred twenty-three million, two hundred eleven thousand, four hundred twenty-one".