820001378 has 12 divisors (see below), whose sum is σ = 1430818902. Its totient is φ = 351429120.

The previous prime is 820001333. The next prime is 820001383. The reversal of 820001378 is 873100028.

It can be written as a sum of positive squares in only one way, i.e., 799362529 + 20638849 = 28273^2 + 4543^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 820001378.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4183583 + ... + 4183778.

Almost surely, 2^820001378 is an apocalyptic number.

820001378 is a deficient number, since it is larger than the sum of its proper divisors (610817524).

820001378 is a wasteful number, since it uses less digits than its factorization.

820001378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8367377 (or 8367370 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 820001378 is about 28635.6661874663. Note that the first 3 decimals coincide. The cubic root of 820001378 is about 935.9906866205.

The spelling of 820001378 in words is "eight hundred twenty million, one thousand, three hundred seventy-eight".