78223731506 has 8 divisors (see below), whose sum is σ = 117341101980. Its totient is φ = 39110030848.

The previous prime is 78223731499. The next prime is 78223731647. The reversal of 78223731506 is 60513732287.

It can be written as a sum of positive squares in 2 ways, for example, as 76361032225 + 1862699281 = 276335^2 + 43159^2 .

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

It is a super-2 number, since 2×78223731506² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 863531 + ... + 949806.

Almost surely, 2^78223731506 is an apocalyptic number.

78223731506 is a deficient number, since it is larger than the sum of its proper divisors (39117370474).

78223731506 is a wasteful number, since it uses less digits than its factorization.

78223731506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1834908.

The product of its (nonzero) digits is 423360, while the sum is 44.

The spelling of 78223731506 in words is "seventy-eight billion, two hundred twenty-three million, seven hundred thirty-one thousand, five hundred six".