61531813516 has 12 divisors (see below), whose sum is σ = 107806917232. Its totient is φ = 30729837168.

The previous prime is 61531813513. The next prime is 61531813523.

It is a happy number.

61531813516 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (61531813513) 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 3 ways as a sum of consecutive naturals, for example, 9013560 + ... + 9020383.

Almost surely, 2^61531813516 is an apocalyptic number.

It is an amenable number.

61531813516 is a deficient number, since it is larger than the sum of its proper divisors (46275103716).

61531813516 is a wasteful number, since it uses less digits than its factorization.

61531813516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18034800 (or 18034798 counting only the distinct ones).

The product of its digits is 64800, while the sum is 40.

The spelling of 61531813516 in words is "sixty-one billion, five hundred thirty-one million, eight hundred thirteen thousand, five hundred sixteen".