18887690 has 8 divisors (see below), whose sum is σ = 33997860. Its totient is φ = 7555072.

The previous prime is 18887689. The next prime is 18887699. The reversal of 18887690 is 9678881.

It can be written as a sum of positive squares in 2 ways, for example, as 17783089 + 1104601 = 4217^2 + 1051^2 .

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

It is a super-2 number, since 2×18887690² = 713489667072200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18887699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 944375 + ... + 944394.

Almost surely, 2^18887690 is an apocalyptic number.

18887690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18887690 is a deficient number, since it is larger than the sum of its proper divisors (15110170).

18887690 is a wasteful number, since it uses less digits than its factorization.

18887690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888776.

The product of its (nonzero) digits is 193536, while the sum is 47.

The square root of 18887690 is about 4345.9970087426. The cubic root of 18887690 is about 266.3133567549.

It can be divided in two parts, 188 and 87690, that added together give a palindrome (87878).

The spelling of 18887690 in words is "eighteen million, eight hundred eighty-seven thousand, six hundred ninety".