20782781288 has 16 divisors (see below), whose sum is σ = 38975134500. Its totient is φ = 10389412096.

The previous prime is 20782781281. The next prime is 20782781293. The reversal of 20782781288 is 88218728702.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12392587684 + 8390193604 = 111322^2 + 91598^2 .

It is not an unprimeable number, because it can be changed into a prime (20782781281) 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, 202193 + ... + 287136.

Almost surely, 2^20782781288 is an apocalyptic number.

It is an amenable number.

20782781288 is a deficient number, since it is larger than the sum of its proper divisors (18192353212).

20782781288 is a wasteful number, since it uses less digits than its factorization.

20782781288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494644 (or 494640 counting only the distinct ones).

The product of its (nonzero) digits is 1605632, while the sum is 53.

The spelling of 20782781288 in words is "twenty billion, seven hundred eighty-two million, seven hundred eighty-one thousand, two hundred eighty-eight".