61531321161 has 8 divisors (see below), whose sum is σ = 82409662720. Its totient is φ = 40836930192.

The previous prime is 61531321141. The next prime is 61531321169. The reversal of 61531321161 is 16112313516.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61531321161 - 2¹⁵ = 61531288393 is a prime.

It is a super-2 number, since 2×61531321161² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61531321169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45986866 + ... + 45988203.

It is an arithmetic number, because the mean of its divisors is an integer number (10301207840).

Almost surely, 2^61531321161 is an apocalyptic number.

It is an amenable number.

61531321161 is a deficient number, since it is larger than the sum of its proper divisors (20878341559).

61531321161 is a wasteful number, since it uses less digits than its factorization.

61531321161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91975295.

The product of its digits is 3240, while the sum is 30.

Adding to 61531321161 its reverse (16112313516), we get a palindrome (77643634677).

The spelling of 61531321161 in words is "sixty-one billion, five hundred thirty-one million, three hundred twenty-one thousand, one hundred sixty-one".