7121818 has 12 divisors (see below), whose sum is σ = 11742570. Its totient is φ = 3237080.

The previous prime is 7121809. The next prime is 7121819. The reversal of 7121818 is 8181217.

It can be written as a sum of positive squares in only one way, i.e., 4507129 + 2614689 = 2123^2 + 1617^2 .

7121818 is a modest number, since divided by 1818 gives 712 as remainder.

It is not an unprimeable number, because it can be changed into a prime (7121819) 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 5 ways as a sum of consecutive naturals, for example, 14473 + ... + 14956.

Almost surely, 2^7121818 is an apocalyptic number.

7121818 is a deficient number, since it is larger than the sum of its proper divisors (4620752).

7121818 is a wasteful number, since it uses less digits than its factorization.

7121818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29453 (or 29442 counting only the distinct ones).

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

The square root of 7121818 is about 2668.6734532348. The cubic root of 7121818 is about 192.3964068468.

The spelling of 7121818 in words is "seven million, one hundred twenty-one thousand, eight hundred eighteen".