21047417 has 8 divisors (see below), whose sum is σ = 22051200. Its totient is φ = 20062224.

The previous prime is 21047407. The next prime is 21047423. The reversal of 21047417 is 71474012.

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 21047417 - 2⁴ = 21047401 is a prime.

It is a super-3 number, since 3×21047417³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21047407) 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, 2303 + ... + 6884.

It is an arithmetic number, because the mean of its divisors is an integer number (2756400).

Almost surely, 2^21047417 is an apocalyptic number.

It is an amenable number.

21047417 is a deficient number, since it is larger than the sum of its proper divisors (1003783).

21047417 is an equidigital number, since it uses as much as digits as its factorization.

21047417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9295.

The product of its (nonzero) digits is 1568, while the sum is 26.

The square root of 21047417 is about 4587.7463966527. The cubic root of 21047417 is about 276.0999121925.

The spelling of 21047417 in words is "twenty-one million, forty-seven thousand, four hundred seventeen".