111121656109 has 2 divisors, whose sum is σ = 111121656110. Its totient is φ = 111121656108.

The previous prime is 111121656103. The next prime is 111121656133. The reversal of 111121656109 is 901656121111.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111024239209 + 97416900 = 333203^2 + 9870^2 .

It is a cyclic number.

It is not a de Polignac number, because 111121656109 - 2¹⁵ = 111121623341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111121656103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55560828054 + 55560828055.

It is an arithmetic number, because the mean of its divisors is an integer number (55560828055).

Almost surely, 2^111121656109 is an apocalyptic number.

It is an amenable number.

111121656109 is a deficient number, since it is larger than the sum of its proper divisors (1).

111121656109 is an equidigital number, since it uses as much as digits as its factorization.

111121656109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 34.

The spelling of 111121656109 in words is "one hundred eleven billion, one hundred twenty-one million, six hundred fifty-six thousand, one hundred nine".