7111720615661 has 8 divisors (see below), whose sum is σ = 7332659926944. Its totient is φ = 6893306325360.

The previous prime is 7111720615639. The next prime is 7111720615669. The reversal of 7111720615661 is 1665160271117.

7111720615661 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 7111720615661 - 2²² = 7111716421357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7111720615669) 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, 631249526 + ... + 631260791.

It is an arithmetic number, because the mean of its divisors is an integer number (916582490868).

Almost surely, 2^{7111720615661} is an apocalyptic number.

It is an amenable number.

7111720615661 is a deficient number, since it is larger than the sum of its proper divisors (220939311283).

7111720615661 is a wasteful number, since it uses less digits than its factorization.

7111720615661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1262510491.

The product of its (nonzero) digits is 105840, while the sum is 44.

Adding to 7111720615661 its reverse (1665160271117), we get a palindrome (8776880886778).

The spelling of 7111720615661 in words is "seven trillion, one hundred eleven billion, seven hundred twenty million, six hundred fifteen thousand, six hundred sixty-one".