21331457827 has 4 divisors (see below), whose sum is σ = 21391887240. Its totient is φ = 21271028416.

The previous prime is 21331457803. The next prime is 21331457831. The reversal of 21331457827 is 72875413312.

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-21331457827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21331457857) 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, 30214177 + ... + 30214882.

It is an arithmetic number, because the mean of its divisors is an integer number (5347971810).

Almost surely, 2^21331457827 is an apocalyptic number.

21331457827 is a deficient number, since it is larger than the sum of its proper divisors (60429413).

21331457827 is an equidigital number, since it uses as much as digits as its factorization.

21331457827 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60429412.

The product of its digits is 282240, while the sum is 43.

The spelling of 21331457827 in words is "twenty-one billion, three hundred thirty-one million, four hundred fifty-seven thousand, eight hundred twenty-seven".