818078121506 has 16 divisors (see below), whose sum is σ = 1247353612920. Its totient is φ = 402294871680.

The previous prime is 818078121491. The next prime is 818078121529. The reversal of 818078121506 is 605121870818.

It can be written as a sum of positive squares in 4 ways, for example, as 243946100281 + 574132021225 = 493909^2 + 757715^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 975230 + ... + 1608486.

Almost surely, 2^818078121506 is an apocalyptic number.

818078121506 is a deficient number, since it is larger than the sum of its proper divisors (429275491414).

818078121506 is a wasteful number, since it uses less digits than its factorization.

818078121506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643909.

The product of its (nonzero) digits is 215040, while the sum is 47.

The spelling of 818078121506 in words is "eight hundred eighteen billion, seventy-eight million, one hundred twenty-one thousand, five hundred six".