21254763 has 8 divisors (see below), whose sum is σ = 28942848. Its totient is φ = 13868264.

The previous prime is 21254729. The next prime is 21254789. The reversal of 21254763 is 36745212.

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 21254763 - 2²⁰ = 20206187 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 21254763.

It is not an unprimeable number, because it can be changed into a prime (21254263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75231 + ... + 75512.

It is an arithmetic number, because the mean of its divisors is an integer number (3617856).

Almost surely, 2^21254763 is an apocalyptic number.

21254763 is a deficient number, since it is larger than the sum of its proper divisors (7688085).

21254763 is a wasteful number, since it uses less digits than its factorization.

21254763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150793.

The product of its digits is 10080, while the sum is 30.

The square root of 21254763 is about 4610.2888195860. The cubic root of 21254763 is about 277.0036057171.

Adding to 21254763 its reverse (36745212), we get a palindrome (57999975).

The spelling of 21254763 in words is "twenty-one million, two hundred fifty-four thousand, seven hundred sixty-three".