21047287893 has 8 divisors (see below), whose sum is σ = 28066434048. Its totient is φ = 14029833504.

The previous prime is 21047287883. The next prime is 21047287931. The reversal of 21047287893 is 39878274012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21047287893 - 2⁵ = 21047287861 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21047287813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 393621 + ... + 443882.

It is an arithmetic number, because the mean of its divisors is an integer number (3508304256).

Almost surely, 2^21047287893 is an apocalyptic number.

It is an amenable number.

21047287893 is a deficient number, since it is larger than the sum of its proper divisors (7019146155).

21047287893 is an equidigital number, since it uses as much as digits as its factorization.

21047287893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845883.

The product of its (nonzero) digits is 1354752, while the sum is 51.

The spelling of 21047287893 in words is "twenty-one billion, forty-seven million, two hundred eighty-seven thousand, eight hundred ninety-three".