20453421 has 4 divisors (see below), whose sum is σ = 27271232. Its totient is φ = 13635612.

The previous prime is 20453401. The next prime is 20453437. The reversal of 20453421 is 12435402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20453421 - 2¹¹ = 20451373 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 (20453401) 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, 3408901 + ... + 3408906.

It is an arithmetic number, because the mean of its divisors is an integer number (6817808).

Almost surely, 2^20453421 is an apocalyptic number.

It is an amenable number.

20453421 is a deficient number, since it is larger than the sum of its proper divisors (6817811).

20453421 is an equidigital number, since it uses as much as digits as its factorization.

20453421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6817810.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20453421 is about 4522.5458538306. The cubic root of 20453421 is about 273.4777422851.

Adding to 20453421 its reverse (12435402), we get a palindrome (32888823).

The spelling of 20453421 in words is "twenty million, four hundred fifty-three thousand, four hundred twenty-one".