20001421 has 12 divisors (see below), whose sum is σ = 22944096. Its totient is φ = 17390120.

The previous prime is 20001389. The next prime is 20001439. The reversal of 20001421 is 12410002.

It is not a de Polignac number, because 20001421 - 2⁵ = 20001389 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20001398 and 20001407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 811 + ... + 6376.

It is an arithmetic number, because the mean of its divisors is an integer number (1912008).

Almost surely, 2^20001421 is an apocalyptic number.

It is an amenable number.

20001421 is a deficient number, since it is larger than the sum of its proper divisors (2942675).

20001421 is a wasteful number, since it uses less digits than its factorization.

20001421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7232 (or 7221 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 20001421 is about 4472.2948248075. The cubic root of 20001421 is about 271.4481901530.

Adding to 20001421 its reverse (12410002), we get a palindrome (32411423).

The spelling of 20001421 in words is "twenty million, one thousand, four hundred twenty-one".