20047421 has 12 divisors (see below), whose sum is σ = 21639456. Its totient is φ = 18536760.

The previous prime is 20047411. The next prime is 20047453. The reversal of 20047421 is 12474002.

It is not a de Polignac number, because 20047421 - 2¹⁸ = 19785277 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20047393 and 20047402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20047411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21650 + ... + 22556.

It is an arithmetic number, because the mean of its divisors is an integer number (1803288).

Almost surely, 2^20047421 is an apocalyptic number.

It is an amenable number.

20047421 is a deficient number, since it is larger than the sum of its proper divisors (1592035).

20047421 is an equidigital number, since it uses as much as digits as its factorization.

20047421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992 (or 961 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 20047421 is about 4477.4346449725. The cubic root of 20047421 is about 271.6561263219.

The spelling of 20047421 in words is "twenty million, forty-seven thousand, four hundred twenty-one".