21717469 has 4 divisors (see below), whose sum is σ = 21920544. Its totient is φ = 21514396.

The previous prime is 21717463. The next prime is 21717473. The reversal of 21717469 is 96471712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21717469 - 2³ = 21717461 is a prime.

It is a super-2 number, since 2×21717469² = 943296919531922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21717461) 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, 101377 + ... + 101590.

It is an arithmetic number, because the mean of its divisors is an integer number (5480136).

Almost surely, 2^21717469 is an apocalyptic number.

It is an amenable number.

21717469 is a deficient number, since it is larger than the sum of its proper divisors (203075).

21717469 is a wasteful number, since it uses less digits than its factorization.

21717469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203074.

The product of its digits is 21168, while the sum is 37.

The square root of 21717469 is about 4660.2005321660. The cubic root of 21717469 is about 278.9992720184. Note that the first 3 decimals are identical.

The spelling of 21717469 in words is "twenty-one million, seven hundred seventeen thousand, four hundred sixty-nine".