18421565696 has 18 divisors (see below), whose sum is σ = 36771172662. Its totient is φ = 9210782720.

The previous prime is 18421565677. The next prime is 18421565699. The reversal of 18421565696 is 69656512481.

It can be written as a sum of positive squares in only one way, i.e., 18409062400 + 12503296 = 135680^2 + 3536^2 .

It is not an unprimeable number, because it can be changed into a prime (18421565699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35979365 + ... + 35979876.

Almost surely, 2^18421565696 is an apocalyptic number.

18421565696 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18421565696 is a deficient number, since it is larger than the sum of its proper divisors (18349606966).

18421565696 is an frugal number, since it uses more digits than its factorization.

18421565696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71959257 (or 71959243 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 53.

The spelling of 18421565696 in words is "eighteen billion, four hundred twenty-one million, five hundred sixty-five thousand, six hundred ninety-six".