20888421 has 4 divisors (see below), whose sum is σ = 27851232. Its totient is φ = 13925612.

The previous prime is 20888383. The next prime is 20888423. The reversal of 20888421 is 12488802.

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 a cyclic number.

It is not a de Polignac number, because 20888421 - 2¹⁷ = 20757349 is a prime.

It is a super-2 number, since 2×20888421² = 872652263746482, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20888423) 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, 3481401 + ... + 3481406.

It is an arithmetic number, because the mean of its divisors is an integer number (6962808).

Almost surely, 2^20888421 is an apocalyptic number.

It is an amenable number.

20888421 is a deficient number, since it is larger than the sum of its proper divisors (6962811).

20888421 is an equidigital number, since it uses as much as digits as its factorization.

20888421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6962810.

The product of its (nonzero) digits is 8192, while the sum is 33.

The square root of 20888421 is about 4570.3852135241. The cubic root of 20888421 is about 275.4029179140.

The spelling of 20888421 in words is "twenty million, eight hundred eighty-eight thousand, four hundred twenty-one".