21582328523 has 4 divisors (see below), whose sum is σ = 24665518320. Its totient is φ = 18499138728.

The previous prime is 21582328519. The next prime is 21582328541. The reversal of 21582328523 is 32582328512.

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

It is not a de Polignac number, because 21582328523 - 2² = 21582328519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21582328543) 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, 1541594888 + ... + 1541594901.

It is an arithmetic number, because the mean of its divisors is an integer number (6166379580).

Almost surely, 2^21582328523 is an apocalyptic number.

21582328523 is a deficient number, since it is larger than the sum of its proper divisors (3083189797).

21582328523 is an equidigital number, since it uses as much as digits as its factorization.

21582328523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3083189796.

The product of its digits is 230400, while the sum is 41.

The spelling of 21582328523 in words is "twenty-one billion, five hundred eighty-two million, three hundred twenty-eight thousand, five hundred twenty-three".