7820161 has 4 divisors (see below), whose sum is σ = 8160192. Its totient is φ = 7480132.

The previous prime is 7820159. The next prime is 7820171. The reversal of 7820161 is 1610287.

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 7820161 - 2¹ = 7820159 is a prime.

It is a super-2 number, since 2×7820161² = 122309836131842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7820101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169981 + ... + 170026.

It is an arithmetic number, because the mean of its divisors is an integer number (2040048).

Almost surely, 2^7820161 is an apocalyptic number.

It is an amenable number.

7820161 is a deficient number, since it is larger than the sum of its proper divisors (340031).

7820161 is a wasteful number, since it uses less digits than its factorization.

7820161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340030.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 7820161 is about 2796.4550774150. The cubic root of 7820161 is about 198.4899693976.

The spelling of 7820161 in words is "seven million, eight hundred twenty thousand, one hundred sixty-one".