18687590434 has 4 divisors (see below), whose sum is σ = 28031385654. Its totient is φ = 9343795216.

The previous prime is 18687590399. The next prime is 18687590437. The reversal of 18687590434 is 43409578681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18605778409 + 81812025 = 136403^2 + 9045^2 .

It is not an unprimeable number, because it can be changed into a prime (18687590437) 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 as a sum of consecutive naturals, namely, 4671897607 + ... + 4671897610.

Almost surely, 2^18687590434 is an apocalyptic number.

18687590434 is a deficient number, since it is larger than the sum of its proper divisors (9343795220).

18687590434 is an equidigital number, since it uses as much as digits as its factorization.

18687590434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9343795219.

The product of its (nonzero) digits is 5806080, while the sum is 55.

The spelling of 18687590434 in words is "eighteen billion, six hundred eighty-seven million, five hundred ninety thousand, four hundred thirty-four".