18400555505 has 8 divisors (see below), whose sum is σ = 22089595752. Its totient is φ = 14714491648.

The previous prime is 18400555501. The next prime is 18400555543. The reversal of 18400555505 is 50555500481.

It can be written as a sum of positive squares in 4 ways, for example, as 6910430641 + 11490124864 = 83129^2 + 107192^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 18400555505 - 2² = 18400555501 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18400555501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 730472 + ... + 755241.

It is an arithmetic number, because the mean of its divisors is an integer number (2761199469).

Almost surely, 2^18400555505 is an apocalyptic number.

It is an amenable number.

18400555505 is a deficient number, since it is larger than the sum of its proper divisors (3689040247).

18400555505 is a wasteful number, since it uses less digits than its factorization.

18400555505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1488195.

The product of its (nonzero) digits is 100000, while the sum is 38.

The spelling of 18400555505 in words is "eighteen billion, four hundred million, five hundred fifty-five thousand, five hundred five".