21153763 has 8 divisors (see below), whose sum is σ = 22766400. Its totient is φ = 19582080.

The previous prime is 21153761. The next prime is 21153791. The reversal of 21153763 is 36735112.

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 21153763 - 2¹ = 21153761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21153761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9163 + ... + 11236.

It is an arithmetic number, because the mean of its divisors is an integer number (2845800).

Almost surely, 2^21153763 is an apocalyptic number.

21153763 is a deficient number, since it is larger than the sum of its proper divisors (1612637).

21153763 is a wasteful number, since it uses less digits than its factorization.

21153763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20477.

The product of its digits is 3780, while the sum is 28.

The square root of 21153763 is about 4599.3220152540. The cubic root of 21153763 is about 276.5641466254.

Adding to 21153763 its reverse (36735112), we get a palindrome (57888875).

It can be divided in two parts, 211537 and 63, that added together give a square (211600 = 460²).

The spelling of 21153763 in words is "twenty-one million, one hundred fifty-three thousand, seven hundred sixty-three".