61171561 has 4 divisors (see below), whose sum is σ = 66732624. Its totient is φ = 55610500.

The previous prime is 61171553. The next prime is 61171567. The reversal of 61171561 is 16517116.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 61171561 - 2³ = 61171553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61171567) 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, 2780515 + ... + 2780536.

It is an arithmetic number, because the mean of its divisors is an integer number (16683156).

Almost surely, 2^61171561 is an apocalyptic number.

It is an amenable number.

61171561 is a deficient number, since it is larger than the sum of its proper divisors (5561063).

61171561 is a wasteful number, since it uses less digits than its factorization.

61171561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5561062.

The product of its digits is 1260, while the sum is 28.

The square root of 61171561 is about 7821.2250319243. The cubic root of 61171561 is about 394.0184162589.

Adding to 61171561 its reverse (16517116), we get a palindrome (77688677).

The spelling of 61171561 in words is "sixty-one million, one hundred seventy-one thousand, five hundred sixty-one".