21416417 has 4 divisors (see below), whose sum is σ = 23363376. Its totient is φ = 19469460.

The previous prime is 21416411. The next prime is 21416431. The reversal of 21416417 is 71461412.

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 a de Polignac number, because none of the positive numbers 2^k-21416417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21416411) 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, 973463 + ... + 973484.

It is an arithmetic number, because the mean of its divisors is an integer number (5840844).

Almost surely, 2^21416417 is an apocalyptic number.

It is an amenable number.

21416417 is a deficient number, since it is larger than the sum of its proper divisors (1946959).

21416417 is a wasteful number, since it uses less digits than its factorization.

21416417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1946958.

The product of its digits is 1344, while the sum is 26.

The square root of 21416417 is about 4627.7874843169. The cubic root of 21416417 is about 277.7040870778.

Adding to 21416417 its reverse (71461412), we get a palindrome (92877829).

It can be divided in two parts, 2141 and 6417, that added together give a palindrome (8558).

The spelling of 21416417 in words is "twenty-one million, four hundred sixteen thousand, four hundred seventeen".