1616801605 has 4 divisors (see below), whose sum is σ = 1940161932. Its totient is φ = 1293441280.

The previous prime is 1616801581. The next prime is 1616801611. The reversal of 1616801605 is 5061086161.

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 484748289 + 1132053316 = 22017^2 + 33646^2 .

It is not a de Polignac number, because 1616801605 - 2⁵ = 1616801573 is a prime.

It is a super-2 number, since 2×1616801605² = 5228094859861152050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161680156 + ... + 161680165.

It is an arithmetic number, because the mean of its divisors is an integer number (485040483).

Almost surely, 2^1616801605 is an apocalyptic number.

It is an amenable number.

1616801605 is a deficient number, since it is larger than the sum of its proper divisors (323360327).

1616801605 is an equidigital number, since it uses as much as digits as its factorization.

1616801605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323360326.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 1616801605 is about 40209.4715831979. The cubic root of 1616801605 is about 1173.6868638027.

Adding to 1616801605 its reverse (5061086161), we get a palindrome (6677887766).

The spelling of 1616801605 in words is "one billion, six hundred sixteen million, eight hundred one thousand, six hundred five".