21417645 has 8 divisors (see below), whose sum is σ = 34268256. Its totient is φ = 11422736.

The previous prime is 21417629. The next prime is 21417659. The reversal of 21417645 is 54671412.

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 21417645 - 2⁴ = 21417629 is a prime.

It is a super-3 number, since 3×21417645³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 713907 + ... + 713936.

It is an arithmetic number, because the mean of its divisors is an integer number (4283532).

Almost surely, 2^21417645 is an apocalyptic number.

It is an amenable number.

21417645 is a deficient number, since it is larger than the sum of its proper divisors (12850611).

21417645 is a wasteful number, since it uses less digits than its factorization.

21417645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1427851.

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

The square root of 21417645 is about 4627.9201592076. The cubic root of 21417645 is about 277.7093947521.

The spelling of 21417645 in words is "twenty-one million, four hundred seventeen thousand, six hundred forty-five".