21163351 has 8 divisors (see below), whose sum is σ = 24445584. Its totient is φ = 18107520.

The previous prime is 21163343. The next prime is 21163361. The reversal of 21163351 is 15336112.

It is a happy number.

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 21163351 - 2³ = 21163343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21163361) 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, 56400 + ... + 56773.

It is an arithmetic number, because the mean of its divisors is an integer number (3055698).

Almost surely, 2^21163351 is an apocalyptic number.

21163351 is a deficient number, since it is larger than the sum of its proper divisors (3282233).

21163351 is a wasteful number, since it uses less digits than its factorization.

21163351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113201.

The product of its digits is 540, while the sum is 22.

The square root of 21163351 is about 4600.3642247109. The cubic root of 21163351 is about 276.6059247952.

Adding to 21163351 its reverse (15336112), we get a palindrome (36499463).

The spelling of 21163351 in words is "twenty-one million, one hundred sixty-three thousand, three hundred fifty-one".