7118821 has 4 divisors (see below), whose sum is σ = 7137792. Its totient is φ = 7099852.

The previous prime is 7118807. The next prime is 7118857. The reversal of 7118821 is 1288117.

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 a de Polignac number, because none of the positive numbers 2^k-7118821 is a prime.

It is a super-2 number, since 2×7118821² = 101355224860082, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7118821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7118861) 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, 8911 + ... + 9676.

It is an arithmetic number, because the mean of its divisors is an integer number (1784448).

Almost surely, 2^7118821 is an apocalyptic number.

It is an amenable number.

7118821 is a deficient number, since it is larger than the sum of its proper divisors (18971).

7118821 is a wasteful number, since it uses less digits than its factorization.

7118821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18970.

The product of its digits is 896, while the sum is 28.

The square root of 7118821 is about 2668.1118792135. Note that the first 3 decimals coincide. The cubic root of 7118821 is about 192.3694150059.

It can be divided in two parts, 7 and 118821, that added together give a triangular number (118828 = T₄₈₇).

The spelling of 7118821 in words is "seven million, one hundred eighteen thousand, eight hundred twenty-one".