7661818 has 4 divisors (see below), whose sum is σ = 11492730. Its totient is φ = 3830908.

The previous prime is 7661803. The next prime is 7661821. The reversal of 7661818 is 8181667.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 6436369 + 1225449 = 2537^2 + 1107^2 .

7661818 is a modest number, since divided by 1818 gives 766 as remainder.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1915453 + ... + 1915456.

Almost surely, 2^7661818 is an apocalyptic number.

7661818 is a deficient number, since it is larger than the sum of its proper divisors (3830912).

7661818 is a wasteful number, since it uses less digits than its factorization.

7661818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3830911.

The product of its digits is 16128, while the sum is 37.

The square root of 7661818 is about 2767.9989161848. The cubic root of 7661818 is about 197.1411461529.

It can be divided in two parts, 76618 and 18, that added together give a triangular number (76636 = T₃₉₁).

The spelling of 7661818 in words is "seven million, six hundred sixty-one thousand, eight hundred eighteen".