18728991629 has 4 divisors (see below), whose sum is σ = 18729265884. Its totient is φ = 18728717376.

The previous prime is 18728991623. The next prime is 18728991637. The reversal of 18728991629 is 92619982781.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 4184149225 + 14544842404 = 64685^2 + 120602^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18728991629 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 (18728991623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55589 + ... + 201365.

It is an arithmetic number, because the mean of its divisors is an integer number (4682316471).

Almost surely, 2^18728991629 is an apocalyptic number.

It is an amenable number.

18728991629 is a deficient number, since it is larger than the sum of its proper divisors (274255).

18728991629 is a wasteful number, since it uses less digits than its factorization.

18728991629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274254.

The product of its digits is 7838208, while the sum is 62.

The spelling of 18728991629 in words is "eighteen billion, seven hundred twenty-eight million, nine hundred ninety-one thousand, six hundred twenty-nine".