16219345621 has 4 divisors (see below), whose sum is σ = 16242222700. Its totient is φ = 16196468544.

The previous prime is 16219345613. The next prime is 16219345651. The reversal of 16219345621 is 12654391261.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2836095025 + 13383250596 = 53255^2 + 115686^2 .

It is a cyclic number.

It is not a de Polignac number, because 16219345621 - 2³ = 16219345613 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 (16219345651) 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, 11437476 + ... + 11438893.

It is an arithmetic number, because the mean of its divisors is an integer number (4060555675).

Almost surely, 2^16219345621 is an apocalyptic number.

It is an amenable number.

16219345621 is a deficient number, since it is larger than the sum of its proper divisors (22877079).

16219345621 is an equidigital number, since it uses as much as digits as its factorization.

16219345621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22877078.

The product of its digits is 77760, while the sum is 40.

The spelling of 16219345621 in words is "sixteen billion, two hundred nineteen million, three hundred forty-five thousand, six hundred twenty-one".