18890649 has 6 divisors (see below), whose sum is σ = 27286506. Its totient is φ = 12593760.

The previous prime is 18890611. The next prime is 18890671. The reversal of 18890649 is 94609881.

It can be written as a sum of positive squares in only one way, i.e., 11289600 + 7601049 = 3360^2 + 2757^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18890649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18890149) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1049472 + ... + 1049489.

It is an arithmetic number, because the mean of its divisors is an integer number (4547751).

Almost surely, 2^18890649 is an apocalyptic number.

It is an amenable number.

18890649 is a deficient number, since it is larger than the sum of its proper divisors (8395857).

18890649 is a wasteful number, since it uses less digits than its factorization.

18890649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2098967 (or 2098964 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 18890649 is about 4346.3374236246. The cubic root of 18890649 is about 266.3272631683.

The spelling of 18890649 in words is "eighteen million, eight hundred ninety thousand, six hundred forty-nine".