2161509 has 8 divisors (see below), whose sum is σ = 3293760. Its totient is φ = 1235136.

The previous prime is 2161493. The next prime is 2161513. The reversal of 2161509 is 9051612.

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

It is not a de Polignac number, because 2161509 - 2⁴ = 2161493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161409) 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, 51444 + ... + 51485.

It is an arithmetic number, because the mean of its divisors is an integer number (411720).

2^2161509 is an apocalyptic number.

It is an amenable number.

2161509 is a deficient number, since it is larger than the sum of its proper divisors (1132251).

2161509 is a wasteful number, since it uses less digits than its factorization.

2161509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102939.

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 2161509 is about 1470.2071282646. The cubic root of 2161509 is about 129.2961766350.

The spelling of 2161509 in words is "two million, one hundred sixty-one thousand, five hundred nine".