61651661509197 has 16 divisors (see below), whose sum is σ = 95306916343680. Its totient is φ = 39314102990976.

The previous prime is 61651661509103. The next prime is 61651661509213. The reversal of 61651661509197 is 79190516615616.

It is a happy number.

61651661509197 is a `hidden beast` number, since 6 + 1 + 6 + 5 + 1 + 6 + 615 + 0 + 9 + 1 + 9 + 7 = 666.

It is not a de Polignac number, because 61651661509197 - 2¹² = 61651661505101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61651661505197) 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, 49639018308 + ... + 49639019549.

It is an arithmetic number, because the mean of its divisors is an integer number (5956682271480).

Almost surely, 2^{61651661509197} is an apocalyptic number.

It is an amenable number.

61651661509197 is a deficient number, since it is larger than the sum of its proper divisors (33655254834483).

61651661509197 is a wasteful number, since it uses less digits than its factorization.

61651661509197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99278037889 (or 99278037883 counting only the distinct ones).

The product of its (nonzero) digits is 18370800, while the sum is 63.

The spelling of 61651661509197 in words is "sixty-one trillion, six hundred fifty-one billion, six hundred sixty-one million, five hundred nine thousand, one hundred ninety-seven".