18649557 has 12 divisors (see below), whose sum is σ = 27118624. Its totient is φ = 12349800.

The previous prime is 18649541. The next prime is 18649571. The reversal of 18649557 is 75594681.

It is not a de Polignac number, because 18649557 - 2⁴ = 18649541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18649537) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5503 + ... + 8220.

Almost surely, 2^18649557 is an apocalyptic number.

It is an amenable number.

18649557 is a deficient number, since it is larger than the sum of its proper divisors (8469067).

18649557 is a wasteful number, since it uses less digits than its factorization.

18649557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13880 (or 13877 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 18649557 is about 4318.5132858427. The cubic root of 18649557 is about 265.1894077245.

The spelling of 18649557 in words is "eighteen million, six hundred forty-nine thousand, five hundred fifty-seven".