21263351 has 8 divisors (see below), whose sum is σ = 22084320. Its totient is φ = 20448288.

The previous prime is 21263309. The next prime is 21263353. The reversal of 21263351 is 15336212.

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 21263351 - 2²² = 17069047 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 (21263353) 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, 6710 + ... + 9356.

It is an arithmetic number, because the mean of its divisors is an integer number (2760540).

Almost surely, 2^21263351 is an apocalyptic number.

21263351 is a deficient number, since it is larger than the sum of its proper divisors (820969).

21263351 is a wasteful number, since it uses less digits than its factorization.

21263351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2953.

The product of its digits is 1080, while the sum is 23.

The square root of 21263351 is about 4611.2201205321. The cubic root of 21263351 is about 277.0409085189.

Adding to 21263351 its reverse (15336212), we get a palindrome (36599563).

The spelling of 21263351 in words is "twenty-one million, two hundred sixty-three thousand, three hundred fifty-one".