61666101101 has 4 divisors (see below), whose sum is σ = 67272110304. Its totient is φ = 56060091900.

The previous prime is 61666101089. The next prime is 61666101109. The reversal of 61666101101 is 10110166616.

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 61666101101 - 2¹⁰ = 61666100077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61666101109) 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, 2803004585 + ... + 2803004606.

It is an arithmetic number, because the mean of its divisors is an integer number (16818027576).

Almost surely, 2^61666101101 is an apocalyptic number.

It is an amenable number.

61666101101 is a deficient number, since it is larger than the sum of its proper divisors (5606009203).

61666101101 is a wasteful number, since it uses less digits than its factorization.

61666101101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5606009202.

The product of its (nonzero) digits is 1296, while the sum is 29.

Adding to 61666101101 its reverse (10110166616), we get a palindrome (71776267717).

The spelling of 61666101101 in words is "sixty-one billion, six hundred sixty-six million, one hundred one thousand, one hundred one".