20388892618 has 4 divisors (see below), whose sum is σ = 30583338930. Its totient is φ = 10194446308.

The previous prime is 20388892613. The next prime is 20388892637. The reversal of 20388892618 is 81629888302.

It is a happy number.

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., 18522393409 + 1866499209 = 136097^2 + 43203^2 .

It is not an unprimeable number, because it can be changed into a prime (20388892613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5097223153 + ... + 5097223156.

Almost surely, 2^20388892618 is an apocalyptic number.

20388892618 is a deficient number, since it is larger than the sum of its proper divisors (10194446312).

20388892618 is a wasteful number, since it uses less digits than its factorization.

20388892618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10194446311.

The product of its (nonzero) digits is 2654208, while the sum is 55.

The spelling of 20388892618 in words is "twenty billion, three hundred eighty-eight million, eight hundred ninety-two thousand, six hundred eighteen".