21089990783 has 4 divisors (see below), whose sum is σ = 22006946928. Its totient is φ = 20173034640.

The previous prime is 21089990741. The next prime is 21089990813. The reversal of 21089990783 is 38709998012.

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

It is a cyclic number.

It is not a de Polignac number, because 21089990783 - 2¹⁶ = 21089925247 is a prime.

It is a super-2 number, since 2×21089990783² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21089992783) 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, 458478038 + ... + 458478083.

It is an arithmetic number, because the mean of its divisors is an integer number (5501736732).

Almost surely, 2^21089990783 is an apocalyptic number.

21089990783 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21089990783 is a deficient number, since it is larger than the sum of its proper divisors (916956145).

21089990783 is an equidigital number, since it uses as much as digits as its factorization.

21089990783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916956144.

The product of its (nonzero) digits is 1959552, while the sum is 56.

The spelling of 21089990783 in words is "twenty-one billion, eighty-nine million, nine hundred ninety thousand, seven hundred eighty-three".