51661111061 has 12 divisors (see below), whose sum is σ = 60431317920. Its totient is φ = 44033565240.

The previous prime is 51661111057. The next prime is 51661111063. The reversal of 51661111061 is 16011116615.

It is a happy number.

It is not a de Polignac number, because 51661111061 - 2² = 51661111057 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51661111063) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2936225 + ... + 2953766.

It is an arithmetic number, because the mean of its divisors is an integer number (5035943160).

Almost surely, 2^51661111061 is an apocalyptic number.

It is an amenable number.

51661111061 is a deficient number, since it is larger than the sum of its proper divisors (8770206859).

51661111061 is a wasteful number, since it uses less digits than its factorization.

51661111061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5890184 (or 5890177 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 29.

Adding to 51661111061 its reverse (16011116615), we get a palindrome (67672227676).

The spelling of 51661111061 in words is "fifty-one billion, six hundred sixty-one million, one hundred eleven thousand, sixty-one".