61666681069 has 8 divisors (see below), whose sum is σ = 70477711488. Its totient is φ = 52856026800.

The previous prime is 61666681051. The next prime is 61666681103. The reversal of 61666681069 is 96018666616.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61666681069 - 2⁹ = 61666680557 is a prime.

It is a super-2 number, since 2×61666681069² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61666681169) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 568224 + ... + 667990.

It is an arithmetic number, because the mean of its divisors is an integer number (8809713936).

Almost surely, 2^61666681069 is an apocalyptic number.

It is an amenable number.

61666681069 is a deficient number, since it is larger than the sum of its proper divisors (8811030419).

61666681069 is an equidigital number, since it uses as much as digits as its factorization.

61666681069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188075.

The product of its (nonzero) digits is 3359232, while the sum is 55.

The spelling of 61666681069 in words is "sixty-one billion, six hundred sixty-six million, six hundred eighty-one thousand, sixty-nine".