111110661551 has 2 divisors, whose sum is σ = 111110661552. Its totient is φ = 111110661550.

The previous prime is 111110661547. The next prime is 111110661569. The reversal of 111110661551 is 155166011111.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 111110661551 - 2² = 111110661547 is a prime.

It is a super-2 number, since 2×111110661551² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111110661251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555330775 + 55555330776.

It is an arithmetic number, because the mean of its divisors is an integer number (55555330776).

Almost surely, 2^111110661551 is an apocalyptic number.

111110661551 is a deficient number, since it is larger than the sum of its proper divisors (1).

111110661551 is an equidigital number, since it uses as much as digits as its factorization.

111110661551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 900, while the sum is 29.

Adding to 111110661551 its reverse (155166011111), we get a palindrome (266276672662).

The spelling of 111110661551 in words is "one hundred eleven billion, one hundred ten million, six hundred sixty-one thousand, five hundred fifty-one".