21348717 has 16 divisors (see below), whose sum is σ = 30744000. Its totient is φ = 13099392.

The previous prime is 21348713. The next prime is 21348721. The reversal of 21348717 is 71784312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21348713) and next prime (21348721).

It is not a de Polignac number, because 21348717 - 2² = 21348713 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21348713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18913 + ... + 20009.

It is an arithmetic number, because the mean of its divisors is an integer number (1921500).

Almost surely, 2^21348717 is an apocalyptic number.

It is an amenable number.

21348717 is a deficient number, since it is larger than the sum of its proper divisors (9395283).

21348717 is a wasteful number, since it uses less digits than its factorization.

21348717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1612.

The product of its digits is 9408, while the sum is 33.

The square root of 21348717 is about 4620.4671841709. The cubic root of 21348717 is about 277.4111589644.

The spelling of 21348717 in words is "twenty-one million, three hundred forty-eight thousand, seven hundred seventeen".