20778128 has 20 divisors (see below), whose sum is σ = 46008960. Its totient is φ = 8904864.

The previous prime is 20778113. The next prime is 20778139. The reversal of 20778128 is 82187702.

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, 92648 + ... + 92871.

It is an arithmetic number, because the mean of its divisors is an integer number (2300448).

Almost surely, 2^20778128 is an apocalyptic number.

20778128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20778128 is an abundant number, since it is smaller than the sum of its proper divisors (25230832).

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

20778128 is a wasteful number, since it uses less digits than its factorization.

20778128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185534 (or 185528 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 20778128 is about 4558.3031930752. The cubic root of 20778128 is about 274.9173437537.

The spelling of 20778128 in words is "twenty million, seven hundred seventy-eight thousand, one hundred twenty-eight".