21013763 has 8 divisors (see below), whose sum is σ = 21362880. Its totient is φ = 20666880.

The previous prime is 21013723. The next prime is 21013781. The reversal of 21013763 is 36731012.

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 21013763 - 2⁸ = 21013507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21013723) 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, 36131 + ... + 36707.

It is an arithmetic number, because the mean of its divisors is an integer number (2670360).

Almost surely, 2^21013763 is an apocalyptic number.

21013763 is a deficient number, since it is larger than the sum of its proper divisors (349117).

21013763 is an equidigital number, since it uses as much as digits as its factorization.

21013763 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1117.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 21013763 is about 4584.0771154072. The cubic root of 21013763 is about 275.9526760211.

Adding to 21013763 its reverse (36731012), we get a palindrome (57744775).

The spelling of 21013763 in words is "twenty-one million, thirteen thousand, seven hundred sixty-three".