21516494783 has 16 divisors (see below), whose sum is σ = 24648869376. Its totient is φ = 18398830560.

The previous prime is 21516494761. The next prime is 21516494789. The reversal of 21516494783 is 38749461512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21516494783 - 2¹⁰ = 21516493759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21516494789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6473360 + ... + 6476682.

It is an arithmetic number, because the mean of its divisors is an integer number (1540554336).

Almost surely, 2^21516494783 is an apocalyptic number.

21516494783 is a deficient number, since it is larger than the sum of its proper divisors (3132374593).

21516494783 is an equidigital number, since it uses as much as digits as its factorization.

21516494783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5254.

The product of its digits is 1451520, while the sum is 50.

The spelling of 21516494783 in words is "twenty-one billion, five hundred sixteen million, four hundred ninety-four thousand, seven hundred eighty-three".