102661909 has 24 divisors (see below), whose sum is σ = 123559128. Its totient is φ = 84994560.

The previous prime is 102661907. The next prime is 102661913. The reversal of 102661909 is 909166201.

It can be written as a sum of positive squares in 4 ways, for example, as 3161284 + 99500625 = 1778^2 + 9975^2 .

It is not a de Polignac number, because 102661909 - 2¹ = 102661907 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102661907) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 275047 + ... + 275419.

It is an arithmetic number, because the mean of its divisors is an integer number (5148297).

Almost surely, 2^102661909 is an apocalyptic number.

It is an amenable number.

102661909 is a deficient number, since it is larger than the sum of its proper divisors (20897219).

102661909 is a wasteful number, since it uses less digits than its factorization.

102661909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565 (or 558 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 102661909 is about 10132.2213260469. The cubic root of 102661909 is about 468.2413665351.

The spelling of 102661909 in words is "one hundred two million, six hundred sixty-one thousand, nine hundred nine".