18918705 has 48 divisors (see below), whose sum is σ = 34784640. Its totient is φ = 8745984.

The previous prime is 18918619. The next prime is 18918709. The reversal of 18918705 is 50781981.

It is not a de Polignac number, because 18918705 - 2⁷ = 18918577 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18918709) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 42876 + ... + 43314.

It is an arithmetic number, because the mean of its divisors is an integer number (724680).

Almost surely, 2^18918705 is an apocalyptic number.

18918705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18918705 is a deficient number, since it is larger than the sum of its proper divisors (15865935).

18918705 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (18918704) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (477).

18918705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 39.

The square root of 18918705 is about 4349.5637712304. The cubic root of 18918705 is about 266.4590458582.

The spelling of 18918705 in words is "eighteen million, nine hundred eighteen thousand, seven hundred five".