21229517 has 8 divisors (see below), whose sum is σ = 22579200. Its totient is φ = 19903104.

The previous prime is 21229501. The next prime is 21229577. The reversal of 21229517 is 71592212.

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 21229517 - 2⁴ = 21229501 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21229517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21229577) 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, 3917 + ... + 7602.

It is an arithmetic number, because the mean of its divisors is an integer number (2822400).

Almost surely, 2^21229517 is an apocalyptic number.

It is an amenable number.

21229517 is a deficient number, since it is larger than the sum of its proper divisors (1349683).

21229517 is a wasteful number, since it uses less digits than its factorization.

21229517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11635.

The product of its digits is 2520, while the sum is 29.

The square root of 21229517 is about 4607.5499997287. The cubic root of 21229517 is about 276.8938890751.

The spelling of 21229517 in words is "twenty-one million, two hundred twenty-nine thousand, five hundred seventeen".