18518516 has 6 divisors (see below), whose sum is σ = 32407410. Its totient is φ = 9259256.

The previous prime is 18518503. The next prime is 18518531. The reversal of 18518516 is 61581581.

It can be written as a sum of positive squares in only one way, i.e., 18028516 + 490000 = 4246^2 + 700^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2314811 + ... + 2314818.

It is an arithmetic number, because the mean of its divisors is an integer number (5401235).

Almost surely, 2^18518516 is an apocalyptic number.

It is an amenable number.

18518516 is a deficient number, since it is larger than the sum of its proper divisors (13888894).

18518516 is a wasteful number, since it uses less digits than its factorization.

18518516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4629633 (or 4629631 counting only the distinct ones).

The product of its digits is 9600, while the sum is 35.

The square root of 18518516 is about 4303.3145364939. The cubic root of 18518516 is about 264.5668300010.

The spelling of 18518516 in words is "eighteen million, five hundred eighteen thousand, five hundred sixteen".