20552421 has 4 divisors (see below), whose sum is σ = 27403232. Its totient is φ = 13701612.

The previous prime is 20552417. The next prime is 20552423. The reversal of 20552421 is 12425502.

It is a happy number.

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 20552421 - 2² = 20552417 is a prime.

It is a super-2 number, since 2×20552421² = 844804017922482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20552423) 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, 3425401 + ... + 3425406.

It is an arithmetic number, because the mean of its divisors is an integer number (6850808).

Almost surely, 2^20552421 is an apocalyptic number.

It is an amenable number.

20552421 is a deficient number, since it is larger than the sum of its proper divisors (6850811).

20552421 is an equidigital number, since it uses as much as digits as its factorization.

20552421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6850810.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 20552421 is about 4533.4778040705. The cubic root of 20552421 is about 273.9182673087.

Adding to 20552421 its reverse (12425502), we get a palindrome (32977923).

The spelling of 20552421 in words is "twenty million, five hundred fifty-two thousand, four hundred twenty-one".