20778284 has 12 divisors (see below), whose sum is σ = 38501064. Its totient is φ = 9777984.

The previous prime is 20778283. The next prime is 20778287. The reversal of 20778284 is 48287702.

It is not an unprimeable number, because it can be changed into a prime (20778283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152714 + ... + 152849.

It is an arithmetic number, because the mean of its divisors is an integer number (3208422).

Almost surely, 2^20778284 is an apocalyptic number.

It is an amenable number.

20778284 is a deficient number, since it is larger than the sum of its proper divisors (17722780).

20778284 is a wasteful number, since it uses less digits than its factorization.

20778284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305584 (or 305582 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 38.

The square root of 20778284 is about 4558.3203046736. The cubic root of 20778284 is about 274.9180317688.

The spelling of 20778284 in words is "twenty million, seven hundred seventy-eight thousand, two hundred eighty-four".