4778891820 has 36 divisors (see below), whose sum is σ = 14495972400. Its totient is φ = 1274371104.

The previous prime is 4778891813. The next prime is 4778891833. The reversal of 4778891820 is 281988774.

It is a happy number.

4778891820 is a `hidden beast` number, since 477 + 8 + 8 + 91 + 82 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13274520 + ... + 13274879.

It is an arithmetic number, because the mean of its divisors is an integer number (402665900).

Almost surely, 2^4778891820 is an apocalyptic number.

It is an amenable number.

4778891820 is an abundant number, since it is smaller than the sum of its proper divisors (9717080580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

4778891820 is a wasteful number, since it uses less digits than its factorization.

4778891820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26549414 (or 26549409 counting only the distinct ones).

The product of its (nonzero) digits is 1806336, while the sum is 54.

The square root of 4778891820 is about 69129.5292910345. The cubic root of 4778891820 is about 1684.3890126318.

The spelling of 4778891820 in words is "four billion, seven hundred seventy-eight million, eight hundred ninety-one thousand, eight hundred twenty".