61511145231 has 16 divisors (see below), whose sum is σ = 82108857600. Its totient is φ = 40960465728.

The previous prime is 61511145229. The next prime is 61511145233. The reversal of 61511145231 is 13254111516.

It is an interprime number because it is at equal distance from previous prime (61511145229) and next prime (61511145233).

It is not a de Polignac number, because 61511145231 - 2¹ = 61511145229 is a prime.

It is a super-3 number, since 3×61511145231³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61511145233) 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 15 ways as a sum of consecutive naturals, for example, 16449360 + ... + 16453098.

It is an arithmetic number, because the mean of its divisors is an integer number (5131803600).

Almost surely, 2^61511145231 is an apocalyptic number.

61511145231 is a deficient number, since it is larger than the sum of its proper divisors (20597712369).

61511145231 is a wasteful number, since it uses less digits than its factorization.

61511145231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8558.

The product of its digits is 3600, while the sum is 30.

Adding to 61511145231 its reverse (13254111516), we get a palindrome (74765256747).

The spelling of 61511145231 in words is "sixty-one billion, five hundred eleven million, one hundred forty-five thousand, two hundred thirty-one".