20416421 has 8 divisors (see below), whose sum is σ = 20786304. Its totient is φ = 20049120.

The previous prime is 20416391. The next prime is 20416453. The reversal of 20416421 is 12461402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20416421 - 2¹⁰ = 20415397 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20416393 and 20416402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20416021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21956 + ... + 22866.

It is an arithmetic number, because the mean of its divisors is an integer number (2598288).

Almost surely, 2^20416421 is an apocalyptic number.

It is an amenable number.

20416421 is a deficient number, since it is larger than the sum of its proper divisors (369883).

20416421 is an equidigital number, since it uses as much as digits as its factorization.

20416421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1291.

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

The square root of 20416421 is about 4518.4533858390. The cubic root of 20416421 is about 273.3127367321.

Adding to 20416421 its reverse (12461402), we get a palindrome (32877823).

The spelling of 20416421 in words is "twenty million, four hundred sixteen thousand, four hundred twenty-one".