61643949697 has 4 divisors (see below), whose sum is σ = 67247945136. Its totient is φ = 56039954260.

The previous prime is 61643949683. The next prime is 61643949701. The reversal of 61643949697 is 79694934616.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61643949697 - 2¹¹ = 61643947649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61643949797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2801997703 + ... + 2801997724.

It is an arithmetic number, because the mean of its divisors is an integer number (16811986284).

Almost surely, 2^61643949697 is an apocalyptic number.

It is an amenable number.

61643949697 is a deficient number, since it is larger than the sum of its proper divisors (5603995439).

61643949697 is a wasteful number, since it uses less digits than its factorization.

61643949697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5603995438.

The product of its digits is 52907904, while the sum is 64.

The spelling of 61643949697 in words is "sixty-one billion, six hundred forty-three million, nine hundred forty-nine thousand, six hundred ninety-seven".