7842121 has 4 divisors (see below), whose sum is σ = 8962432. Its totient is φ = 6721812.

The previous prime is 7842119. The next prime is 7842127. The reversal of 7842121 is 1212487.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 7842121 - 2¹ = 7842119 is a prime.

It is a super-2 number, since 2×7842121² = 122997723557282, which contains 22 as substring.

It is a Duffinian number.

7842121 is a modest number, since divided by 2121 gives 784 as remainder.

It is not an unprimeable number, because it can be changed into a prime (7842127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 560145 + ... + 560158.

It is an arithmetic number, because the mean of its divisors is an integer number (2240608).

Almost surely, 2^7842121 is an apocalyptic number.

It is an amenable number.

7842121 is a deficient number, since it is larger than the sum of its proper divisors (1120311).

7842121 is a wasteful number, since it uses less digits than its factorization.

7842121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1120310.

The product of its digits is 896, while the sum is 25.

The square root of 7842121 is about 2800.3787243871. The cubic root of 7842121 is about 198.6755907262.

The spelling of 7842121 in words is "seven million, eight hundred forty-two thousand, one hundred twenty-one".