111151601561 has 16 divisors (see below), whose sum is σ = 149238515328. Its totient is φ = 79949203200.

The previous prime is 111151601549. The next prime is 111151601573. The reversal of 111151601561 is 165106151111.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (111151601549) and next prime (111151601573).

It is a cyclic number.

It is not a de Polignac number, because 111151601561 - 2³⁰ = 110077859737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (111151601261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55519280 + ... + 55521281.

It is an arithmetic number, because the mean of its divisors is an integer number (9327407208).

Almost surely, 2^111151601561 is an apocalyptic number.

111151601561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111151601561 is a deficient number, since it is larger than the sum of its proper divisors (38086913767).

111151601561 is a wasteful number, since it uses less digits than its factorization.

111151601561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111040592.

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

Adding to 111151601561 its reverse (165106151111), we get a palindrome (276257752672).

The spelling of 111151601561 in words is "one hundred eleven billion, one hundred fifty-one million, six hundred one thousand, five hundred sixty-one".