18709489 has 4 divisors (see below), whose sum is σ = 19165860. Its totient is φ = 18253120.

The previous prime is 18709487. The next prime is 18709499. The reversal of 18709489 is 98490781.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1345600 + 17363889 = 1160^2 + 4167^2 .

It is a cyclic number.

It is not a de Polignac number, because 18709489 - 2¹ = 18709487 is a prime.

It is a super-2 number, since 2×18709489² = 700089957282242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18709487) 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, 228124 + ... + 228205.

It is an arithmetic number, because the mean of its divisors is an integer number (4791465).

Almost surely, 2^18709489 is an apocalyptic number.

It is an amenable number.

18709489 is a deficient number, since it is larger than the sum of its proper divisors (456371).

18709489 is an equidigital number, since it uses as much as digits as its factorization.

18709489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456370.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 18709489 is about 4325.4466821358. The cubic root of 18709489 is about 265.4731738400.

The spelling of 18709489 in words is "eighteen million, seven hundred nine thousand, four hundred eighty-nine".