61561562671 has 4 divisors (see below), whose sum is σ = 70356071632. Its totient is φ = 52767053712.

The previous prime is 61561562653. The next prime is 61561562687. The reversal of 61561562671 is 17626516516.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61561562671 - 2¹³ = 61561554479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61561562641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4397254470 + ... + 4397254483.

It is an arithmetic number, because the mean of its divisors is an integer number (17589017908).

Almost surely, 2^61561562671 is an apocalyptic number.

61561562671 is a deficient number, since it is larger than the sum of its proper divisors (8794508961).

61561562671 is an equidigital number, since it uses as much as digits as its factorization.

61561562671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8794508960.

The product of its digits is 453600, while the sum is 46.

The spelling of 61561562671 in words is "sixty-one billion, five hundred sixty-one million, five hundred sixty-two thousand, six hundred seventy-one".