20131421 has 4 divisors (see below), whose sum is σ = 20330844. Its totient is φ = 19932000.

The previous prime is 20131399. The next prime is 20131427. The reversal of 20131421 is 12413102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19483396 + 648025 = 4414^2 + 805^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20131421 is a prime.

It is a super-2 number, since 2×20131421² = 810548222958482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20131396 and 20131405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20131427) 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, 99560 + ... + 99761.

It is an arithmetic number, because the mean of its divisors is an integer number (5082711).

Almost surely, 2^20131421 is an apocalyptic number.

It is an amenable number.

20131421 is a deficient number, since it is larger than the sum of its proper divisors (199423).

20131421 is a wasteful number, since it uses less digits than its factorization.

20131421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199422.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 20131421 is about 4486.8052108377. The cubic root of 20131421 is about 272.0350165775.

Adding to 20131421 its reverse (12413102), we get a palindrome (32544523).

The spelling of 20131421 in words is "twenty million, one hundred thirty-one thousand, four hundred twenty-one".