21748978489 has 8 divisors (see below), whose sum is σ = 24859440128. Its totient is φ = 18639383040.

The previous prime is 21748978487. The next prime is 21748978507. The reversal of 21748978489 is 98487984712.

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

It is a cyclic number.

It is not a de Polignac number, because 21748978489 - 2¹ = 21748978487 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21748978483) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161817 + ... + 263974.

It is an arithmetic number, because the mean of its divisors is an integer number (3107430016).

Almost surely, 2^21748978489 is an apocalyptic number.

It is an amenable number.

21748978489 is a deficient number, since it is larger than the sum of its proper divisors (3110461639).

21748978489 is an equidigital number, since it uses as much as digits as its factorization.

21748978489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433095.

The product of its digits is 65028096, while the sum is 67.

The spelling of 21748978489 in words is "twenty-one billion, seven hundred forty-eight million, nine hundred seventy-eight thousand, four hundred eighty-nine".