21532963 has 4 divisors (see below), whose sum is σ = 21542608. Its totient is φ = 21523320.

The previous prime is 21532961. The next prime is 21532967. The reversal of 21532963 is 36923512.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21532963 - 2¹ = 21532961 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (21532961) 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, 445 + ... + 6577.

It is an arithmetic number, because the mean of its divisors is an integer number (5385652).

Almost surely, 2^21532963 is an apocalyptic number.

21532963 is a deficient number, since it is larger than the sum of its proper divisors (9645).

21532963 is an equidigital number, since it uses as much as digits as its factorization.

21532963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9644.

The product of its digits is 9720, while the sum is 31.

The square root of 21532963 is about 4640.3623780907. The cubic root of 21532963 is about 278.2069220106.

The spelling of 21532963 in words is "twenty-one million, five hundred thirty-two thousand, nine hundred sixty-three".