61609311643 has 4 divisors (see below), whose sum is σ = 67210158168. Its totient is φ = 56008465120.

The previous prime is 61609311587. The next prime is 61609311653. The reversal of 61609311643 is 34611390616.

It is a happy number.

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 61609311643 - 2¹³ = 61609303451 is a prime.

It is a super-2 number, since 2×61609311643² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61609311596 and 61609311605.

It is not an unprimeable number, because it can be changed into a prime (61609311653) 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, 2800423246 + ... + 2800423267.

It is an arithmetic number, because the mean of its divisors is an integer number (16802539542).

Almost surely, 2^61609311643 is an apocalyptic number.

61609311643 is a deficient number, since it is larger than the sum of its proper divisors (5600846525).

61609311643 is a wasteful number, since it uses less digits than its factorization.

61609311643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5600846524.

The product of its (nonzero) digits is 69984, while the sum is 40.

The spelling of 61609311643 in words is "sixty-one billion, six hundred nine million, three hundred eleven thousand, six hundred forty-three".