18888649 has 8 divisors (see below), whose sum is σ = 21538440. Its totient is φ = 16409856.

The previous prime is 18888643. The next prime is 18888671. The reversal of 18888649 is 94688881.

It can be written as a sum of positive squares in 4 ways, for example, as 6215049 + 12673600 = 2493^2 + 3560^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18888649 - 2⁷ = 18888521 is a prime.

It is a super-2 number, since 2×18888649² = 713562122090402, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18888596 and 18888605.

It is not an unprimeable number, because it can be changed into a prime (18888643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42514 + ... + 42955.

It is an arithmetic number, because the mean of its divisors is an integer number (2692305).

Almost surely, 2^18888649 is an apocalyptic number.

It is an amenable number.

18888649 is a deficient number, since it is larger than the sum of its proper divisors (2649791).

18888649 is a wasteful number, since it uses less digits than its factorization.

18888649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85499.

The product of its digits is 884736, while the sum is 52.

The square root of 18888649 is about 4346.1073387573. The cubic root of 18888649 is about 266.3178639266.

The spelling of 18888649 in words is "eighteen million, eight hundred eighty-eight thousand, six hundred forty-nine".