21024489817 has 4 divisors (see below), whose sum is σ = 21025264000. Its totient is φ = 21023715636.

The previous prime is 21024489809. The next prime is 21024489821. The reversal of 21024489817 is 71898442012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21024489817 - 2³ = 21024489809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21024481817) 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, 344817 + ... + 401182.

It is an arithmetic number, because the mean of its divisors is an integer number (5256316000).

Almost surely, 2^21024489817 is an apocalyptic number.

It is an amenable number.

21024489817 is a deficient number, since it is larger than the sum of its proper divisors (774183).

21024489817 is an equidigital number, since it uses as much as digits as its factorization.

21024489817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 774182.

The product of its (nonzero) digits is 258048, while the sum is 46.

The spelling of 21024489817 in words is "twenty-one billion, twenty-four million, four hundred eighty-nine thousand, eight hundred seventeen".