2117421 has 10 divisors (see below), whose sum is σ = 3163182. Its totient is φ = 1411560.

The previous prime is 2117419. The next prime is 2117429. The reversal of 2117421 is 1247112.

It can be written as a sum of positive squares in only one way, i.e., 1946025 + 171396 = 1395^2 + 414^2 .

It is not a de Polignac number, because 2117421 - 2¹ = 2117419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2117394 and 2117403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2117429) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 12990 + ... + 13151.

2^2117421 is an apocalyptic number.

It is an amenable number.

2117421 is a deficient number, since it is larger than the sum of its proper divisors (1045761).

2117421 is an equidigital number, since it uses as much as digits as its factorization.

2117421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26153 (or 26144 counting only the distinct ones).

The product of its digits is 112, while the sum is 18.

The square root of 2117421 is about 1455.1360761111. The cubic root of 2117421 is about 128.4110524157.

The spelling of 2117421 in words is "two million, one hundred seventeen thousand, four hundred twenty-one".