21403617 has 8 divisors (see below), whose sum is σ = 28821120. Its totient is φ = 14127600.

The previous prime is 21403579. The next prime is 21403621. The reversal of 21403617 is 71630412.

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

It is not a de Polignac number, because 21403617 - 2¹⁰ = 21402593 is a prime.

It is a super-2 number, since 2×21403617² = 916229641365378, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21403667) 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, 35017 + ... + 35622.

It is an arithmetic number, because the mean of its divisors is an integer number (3602640).

Almost surely, 2^21403617 is an apocalyptic number.

It is an amenable number.

21403617 is a deficient number, since it is larger than the sum of its proper divisors (7417503).

21403617 is a wasteful number, since it uses less digits than its factorization.

21403617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70743.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21403617 is about 4626.4043273367. The cubic root of 21403617 is about 277.6487507017.

The spelling of 21403617 in words is "twenty-one million, four hundred three thousand, six hundred seventeen".