813321316012778 has 8 divisors (see below), whose sum is σ = 1236694055855268. Its totient is φ = 401089964061024.

The previous prime is 813321316012769. The next prime is 813321316012801. The reversal of 813321316012778 is 877210613123318.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 798228223102489 + 15093092910289 = 28252933^2 + 3884983^2 .

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

It is a super-2 number, since 2×813321316012778² (a number of 31 digits) contains 22 as substring.

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, 2785346972501 + ... + 2785346972792.

Almost surely, 2^{813321316012778} is an apocalyptic number.

813321316012778 is a deficient number, since it is larger than the sum of its proper divisors (423372739842490).

813321316012778 is a wasteful number, since it uses less digits than its factorization.

813321316012778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5570693945368.

The product of its (nonzero) digits is 2032128, while the sum is 53.

The spelling of 813321316012778 in words is "eight hundred thirteen trillion, three hundred twenty-one billion, three hundred sixteen million, twelve thousand, seven hundred seventy-eight".