109009861 has 8 divisors (see below), whose sum is σ = 110366424. Its totient is φ = 107658240.

The previous prime is 109009853. The next prime is 109009889. The reversal of 109009861 is 168900901.

It can be written as a sum of positive squares in 4 ways, for example, as 12852225 + 96157636 = 3585^2 + 9806^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 109009861 - 2³ = 109009853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109009961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62481 + ... + 64201.

It is an arithmetic number, because the mean of its divisors is an integer number (13795803).

Almost surely, 2^109009861 is an apocalyptic number.

It is an amenable number.

109009861 is a deficient number, since it is larger than the sum of its proper divisors (1356563).

109009861 is an equidigital number, since it uses as much as digits as its factorization.

109009861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2471.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 109009861 is about 10440.7787544800. The cubic root of 109009861 is about 477.7000227391.

Subtracting 109009861 from its reverse (168900901), we obtain a triangular number (59891040 = T₁₀₉₄₄).

The spelling of 109009861 in words is "one hundred nine million, nine thousand, eight hundred sixty-one".