61209 has 8 divisors (see below), whose sum is σ = 90720. Its totient is φ = 40788.

The previous prime is 61169. The next prime is 61211. The reversal of 61209 is 90216.

It is not a de Polignac number, because 61209 - 2⁸ = 60953 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61191 and 61200.

It is not an unprimeable number, because it can be changed into a prime (61409) 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, 1107 + ... + 1160.

It is an arithmetic number, because the mean of its divisors is an integer number (11340).

2⁶¹²⁰⁹ is an apocalyptic number.

It is an amenable number.

61209 is a deficient number, since it is larger than the sum of its proper divisors (29511).

61209 is a wasteful number, since it uses less digits than its factorization.

61209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2276 (or 2270 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 61209 is about 247.4045270402. The cubic root of 61209 is about 39.4098783926.

The spelling of 61209 in words is "sixty-one thousand, two hundred nine".