110111812561 has 9 divisors (see below), whose sum is σ = 112746714651. Its totient is φ = 107537135832.

The previous prime is 110111812457. The next prime is 110111812571. The reversal of 110111812561 is 165218111011.

The square root of 110111812561 is 331831.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 54016732225 + 56095080336 = 232415^2 + 236844^2 .

It is not a de Polignac number, because 110111812561 - 2⁹ = 110111812049 is a prime.

It is a super-2 number, since 2×110111812561² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (110111812571) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 14264875 + ... + 14272591.

It is an arithmetic number, because the mean of its divisors is an integer number (12527412739).

Almost surely, 2^110111812561 is an apocalyptic number.

110111812561 is the 331831-st square number.

110111812561 is the 165916-th centered octagonal number.

It is an amenable number.

110111812561 is a deficient number, since it is larger than the sum of its proper divisors (2634902090).

110111812561 is an frugal number, since it uses more digits than its factorization.

110111812561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15520 (or 7760 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 28.

Adding to 110111812561 its reverse (165218111011), we get a palindrome (275329923572).

The spelling of 110111812561 in words is "one hundred ten billion, one hundred eleven million, eight hundred twelve thousand, five hundred sixty-one".