100116561 has 16 divisors (see below), whose sum is σ = 137393408. Its totient is φ = 64800000.

The previous prime is 100116551. The next prime is 100116571. The reversal of 100116561 is 165611001.

It is an interprime number because it is at equal distance from previous prime (100116551) and next prime (100116571).

It is not a de Polignac number, because 100116561 - 2¹⁰ = 100115537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100116551) 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, 82761 + ... + 83961.

It is an arithmetic number, because the mean of its divisors is an integer number (8587088).

Almost surely, 2^100116561 is an apocalyptic number.

It is an amenable number.

100116561 is a deficient number, since it is larger than the sum of its proper divisors (37276847).

100116561 is a wasteful number, since it uses less digits than its factorization.

100116561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1992.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 100116561 is about 10005.8263526807. The cubic root of 100116561 is about 464.3391560822.

Adding to 100116561 its reverse (165611001), we get a palindrome (265727562).

It can be divided in two parts, 1001 and 16561, that multiplied together give a palindrome (16577561).

The spelling of 100116561 in words is "one hundred million, one hundred sixteen thousand, five hundred sixty-one".