21650413 has 4 divisors (see below), whose sum is σ = 21947068. Its totient is φ = 21353760.

The previous prime is 21650411. The next prime is 21650437. The reversal of 21650413 is 31405612.

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 12299049 + 9351364 = 3507^2 + 3058^2 .

It is a cyclic number.

It is not a de Polignac number, because 21650413 - 2¹ = 21650411 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21650411) 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, 148218 + ... + 148363.

It is an arithmetic number, because the mean of its divisors is an integer number (5486767).

Almost surely, 2^21650413 is an apocalyptic number.

It is an amenable number.

21650413 is a deficient number, since it is larger than the sum of its proper divisors (296655).

21650413 is an equidigital number, since it uses as much as digits as its factorization.

21650413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296654.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21650413 is about 4653.0004298302. Note that the first 3 decimals coincide. The cubic root of 21650413 is about 278.7118250255.

The spelling of 21650413 in words is "twenty-one million, six hundred fifty thousand, four hundred thirteen".