20815313863778 has 16 divisors (see below), whose sum is σ = 35690222065344. Its totient is φ = 8919142081200.

The previous prime is 20815313863703. The next prime is 20815313863781. The reversal of 20815313863778 is 87736831351802.

It is a super-4 number, since 4×20815313863778⁴ (a number of 54 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (62) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 20815313863778.

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, 142150673 + ... + 142297028.

It is an arithmetic number, because the mean of its divisors is an integer number (2230638879084).

Almost surely, 2^{20815313863778} is an apocalyptic number.

20815313863778 is a deficient number, since it is larger than the sum of its proper divisors (14874908201566).

20815313863778 is a wasteful number, since it uses less digits than its factorization.

20815313863778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284452937.

The product of its (nonzero) digits is 40642560, while the sum is 62.

The spelling of 20815313863778 in words is "twenty trillion, eight hundred fifteen billion, three hundred thirteen million, eight hundred sixty-three thousand, seven hundred seventy-eight".