2120409 has 6 divisors (see below), whose sum is σ = 3062826. Its totient is φ = 1413600.

The previous prime is 2120387. The next prime is 2120411. The reversal of 2120409 is 9040212.

It can be written as a sum of positive squares in only one way, i.e., 2039184 + 81225 = 1428^2 + 285^2 .

It is not a de Polignac number, because 2120409 - 2¹³ = 2112217 is a prime.

It is a super-2 number, since 2×2120409² = 8992268654562, which contains 22 as substring.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 2120391 and 2120400.

It is not an unprimeable number, because it can be changed into a prime (2120429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 117792 + ... + 117809.

It is an arithmetic number, because the mean of its divisors is an integer number (510471).

2^2120409 is an apocalyptic number.

It is an amenable number.

2120409 is a deficient number, since it is larger than the sum of its proper divisors (942417).

2120409 is a wasteful number, since it uses less digits than its factorization.

2120409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235607 (or 235604 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 2120409 is about 1456.1624222593. The cubic root of 2120409 is about 128.4714264719.

The spelling of 2120409 in words is "two million, one hundred twenty thousand, four hundred nine".