7161821 has 4 divisors (see below), whose sum is σ = 7248192. Its totient is φ = 7075452.

The previous prime is 7161793. The next prime is 7161823. The reversal of 7161821 is 1281617.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1281617 = 79 ⋅16223.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7161821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7161823) 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, 43061 + ... + 43226.

It is an arithmetic number, because the mean of its divisors is an integer number (1812048).

Almost surely, 2^7161821 is an apocalyptic number.

It is an amenable number.

7161821 is a deficient number, since it is larger than the sum of its proper divisors (86371).

7161821 is an equidigital number, since it uses as much as digits as its factorization.

7161821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86370.

The product of its digits is 672, while the sum is 26.

The square root of 7161821 is about 2676.1578802455. The cubic root of 7161821 is about 192.7559624202.

The spelling of 7161821 in words is "seven million, one hundred sixty-one thousand, eight hundred twenty-one".