21041578267 has 4 divisors (see below), whose sum is σ = 21956429520. Its totient is φ = 20126727016.

The previous prime is 21041578223. The next prime is 21041578289. The reversal of 21041578267 is 76287514012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21041578267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21041578297) 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, 457425592 + ... + 457425637.

It is an arithmetic number, because the mean of its divisors is an integer number (5489107380).

Almost surely, 2^21041578267 is an apocalyptic number.

21041578267 is a deficient number, since it is larger than the sum of its proper divisors (914851253).

21041578267 is an equidigital number, since it uses as much as digits as its factorization.

21041578267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914851252.

The product of its (nonzero) digits is 188160, while the sum is 43.

The spelling of 21041578267 in words is "twenty-one billion, forty-one million, five hundred seventy-eight thousand, two hundred sixty-seven".