16648783621 has 8 divisors (see below), whose sum is σ = 17638397784. Its totient is φ = 15660311040.

The previous prime is 16648783609. The next prime is 16648783637. The reversal of 16648783621 is 12638784661.

It can be written as a sum of positive squares in 4 ways, for example, as 6119150625 + 10529632996 = 78225^2 + 102614^2 .

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 16648783621 - 2⁵ = 16648783589 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 (16648783661) 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, 255270 + ... + 313783.

It is an arithmetic number, because the mean of its divisors is an integer number (2204799723).

Almost surely, 2^16648783621 is an apocalyptic number.

It is an amenable number.

16648783621 is a deficient number, since it is larger than the sum of its proper divisors (989614163).

16648783621 is a wasteful number, since it uses less digits than its factorization.

16648783621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570791.

The product of its digits is 2322432, while the sum is 52.

The spelling of 16648783621 in words is "sixteen billion, six hundred forty-eight million, seven hundred eighty-three thousand, six hundred twenty-one".