11423020421 has 4 divisors (see below), whose sum is σ = 11423253612. Its totient is φ = 11422787232.

The previous prime is 11423020387. The next prime is 11423020463. The reversal of 11423020421 is 12402032411.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12402032411 = 239 ⋅51891349.

It can be written as a sum of positive squares in 2 ways, for example, as 10581208225 + 841812196 = 102865^2 + 29014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11423020421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 11423020393 and 11423020402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11423020121) 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, 11600 + ... + 151593.

It is an arithmetic number, because the mean of its divisors is an integer number (2855813403).

Almost surely, 2^11423020421 is an apocalyptic number.

It is an amenable number.

11423020421 is a deficient number, since it is larger than the sum of its proper divisors (233191).

11423020421 is an equidigital number, since it uses as much as digits as its factorization.

11423020421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233190.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 11423020421 its reverse (12402032411), we get a palindrome (23825052832).

The spelling of 11423020421 in words is "eleven billion, four hundred twenty-three million, twenty thousand, four hundred twenty-one".