1616543420225 has 12 divisors (see below), whose sum is σ = 2122426420524. Its totient is φ = 1217162104320.

The previous prime is 1616543420207. The next prime is 1616543420243. The reversal of 1616543420225 is 5220243456161.

It is an interprime number because it is at equal distance from previous prime (1616543420207) and next prime (1616543420243).

It can be written as a sum of positive squares in 6 ways, for example, as 19716933889 + 1596826486336 = 140417^2 + 1263656^2 .

It is not a de Polignac number, because 1616543420225 - 2³⁶ = 1547823943489 is a prime.

It is a super-2 number, since 2×1616543420225² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1901815364 + ... + 1901816213.

It is an arithmetic number, because the mean of its divisors is an integer number (176868868377).

Almost surely, 2^{1616543420225} is an apocalyptic number.

It is an amenable number.

1616543420225 is a deficient number, since it is larger than the sum of its proper divisors (505883000299).

1616543420225 is a wasteful number, since it uses less digits than its factorization.

1616543420225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3803631604 (or 3803631599 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 41.

Adding to 1616543420225 its reverse (5220243456161), we get a palindrome (6836786876386).

The spelling of 1616543420225 in words is "one trillion, six hundred sixteen billion, five hundred forty-three million, four hundred twenty thousand, two hundred twenty-five".