21020413 has 8 divisors (see below), whose sum is σ = 22470336. Its totient is φ = 19615200.

The previous prime is 21020411. The next prime is 21020429. The reversal of 21020413 is 31402012.

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 21020413 - 2¹ = 21020411 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020393 and 21020402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020411) 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, 10203 + ... + 12088.

It is an arithmetic number, because the mean of its divisors is an integer number (2808792).

Almost surely, 2^21020413 is an apocalyptic number.

21020413 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21020413 is a deficient number, since it is larger than the sum of its proper divisors (1449923).

21020413 is a wasteful number, since it uses less digits than its factorization.

21020413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22355.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21020413 is about 4584.8023948694. The cubic root of 21020413 is about 275.9817822114.

Adding to 21020413 its reverse (31402012), we get a palindrome (52422425).

The spelling of 21020413 in words is "twenty-one million, twenty thousand, four hundred thirteen".