21532763 has 4 divisors (see below), whose sum is σ = 24608880. Its totient is φ = 18456648.

The previous prime is 21532747. The next prime is 21532781. The reversal of 21532763 is 36723512.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21532763 - 2⁴ = 21532747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21532733) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1538048 + ... + 1538061.

It is an arithmetic number, because the mean of its divisors is an integer number (6152220).

Almost surely, 2^21532763 is an apocalyptic number.

21532763 is a deficient number, since it is larger than the sum of its proper divisors (3076117).

21532763 is an equidigital number, since it uses as much as digits as its factorization.

21532763 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3076116.

The product of its digits is 7560, while the sum is 29.

The square root of 21532763 is about 4640.3408279996. The cubic root of 21532763 is about 278.2060606714.

The spelling of 21532763 in words is "twenty-one million, five hundred thirty-two thousand, seven hundred sixty-three".