18649489 has 4 divisors (see below), whose sum is σ = 18830656. Its totient is φ = 18468324.

The previous prime is 18649471. The next prime is 18649537. The reversal of 18649489 is 98494681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98494681 = 197 ⋅499973.

It is a cyclic number.

It is not a de Polignac number, because 18649489 - 2⁵ = 18649457 is a prime.

It is a super-2 number, since 2×18649489² = 695606879922242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18649429) 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, 90429 + ... + 90634.

It is an arithmetic number, because the mean of its divisors is an integer number (4707664).

Almost surely, 2^18649489 is an apocalyptic number.

It is an amenable number.

18649489 is a deficient number, since it is larger than the sum of its proper divisors (181167).

18649489 is a wasteful number, since it uses less digits than its factorization.

18649489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181166.

The product of its digits is 497664, while the sum is 49.

The square root of 18649489 is about 4318.5054127557. The cubic root of 18649489 is about 265.1890854129.

The spelling of 18649489 in words is "eighteen million, six hundred forty-nine thousand, four hundred eighty-nine".