21654417 has 4 divisors (see below), whose sum is σ = 28872560. Its totient is φ = 14436276.

The previous prime is 21654383. The next prime is 21654419. The reversal of 21654417 is 71445612.

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 not a de Polignac number, because 21654417 - 2⁷ = 21654289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21654419) 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, 3609067 + ... + 3609072.

It is an arithmetic number, because the mean of its divisors is an integer number (7218140).

Almost surely, 2^21654417 is an apocalyptic number.

It is an amenable number.

21654417 is a deficient number, since it is larger than the sum of its proper divisors (7218143).

21654417 is an equidigital number, since it uses as much as digits as its factorization.

21654417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7218142.

The product of its digits is 6720, while the sum is 30.

The square root of 21654417 is about 4653.4306699466. The cubic root of 21654417 is about 278.7290055039.

The spelling of 21654417 in words is "twenty-one million, six hundred fifty-four thousand, four hundred seventeen".