6161205521 has 4 divisors (see below), whose sum is σ = 6161393700. Its totient is φ = 6161017344.

The previous prime is 6161205517. The next prime is 6161205571. The reversal of 6161205521 is 1255021616.

It is a happy number.

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 3473923600 + 2687281921 = 58940^2 + 51839^2 .

It is a cyclic number.

It is not a de Polignac number, because 6161205521 - 2² = 6161205517 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6161205571) 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, 30776 + ... + 115193.

It is an arithmetic number, because the mean of its divisors is an integer number (1540348425).

Almost surely, 2^6161205521 is an apocalyptic number.

It is an amenable number.

6161205521 is a deficient number, since it is larger than the sum of its proper divisors (188179).

6161205521 is a wasteful number, since it uses less digits than its factorization.

6161205521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188178.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 6161205521 is about 78493.3469855885. The cubic root of 6161205521 is about 1833.2508652234.

The spelling of 6161205521 in words is "six billion, one hundred sixty-one million, two hundred five thousand, five hundred twenty-one".