18700649 has 4 divisors (see below), whose sum is σ = 20400720. Its totient is φ = 17000580.

The previous prime is 18700631. The next prime is 18700673. The reversal of 18700649 is 94600781.

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: 94600781 = 11 ⋅8600071.

It is a cyclic number.

It is not a de Polignac number, because 18700649 - 2⁸ = 18700393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18700249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 850019 + ... + 850040.

It is an arithmetic number, because the mean of its divisors is an integer number (5100180).

Almost surely, 2^18700649 is an apocalyptic number.

It is an amenable number.

18700649 is a deficient number, since it is larger than the sum of its proper divisors (1700071).

18700649 is a wasteful number, since it uses less digits than its factorization.

18700649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1700070.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 18700649 is about 4324.4247016222. The cubic root of 18700649 is about 265.4313563330.

The spelling of 18700649 in words is "eighteen million, seven hundred thousand, six hundred forty-nine".