21634413 has 8 divisors (see below), whose sum is σ = 28884000. Its totient is φ = 14403888.

The previous prime is 21634411. The next prime is 21634423. The reversal of 21634413 is 31443612.

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

It is not a de Polignac number, because 21634413 - 2¹ = 21634411 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1863 + ... + 6836.

It is an arithmetic number, because the mean of its divisors is an integer number (3610500).

Almost surely, 2^21634413 is an apocalyptic number.

It is an amenable number.

21634413 is a deficient number, since it is larger than the sum of its proper divisors (7249587).

21634413 is an equidigital number, since it uses as much as digits as its factorization.

21634413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9531.

The product of its digits is 1728, while the sum is 24.

The square root of 21634413 is about 4651.2807913520. The cubic root of 21634413 is about 278.6431506131.

The spelling of 21634413 in words is "twenty-one million, six hundred thirty-four thousand, four hundred thirteen".