20781732328 has 16 divisors (see below), whose sum is σ = 44532283680. Its totient is φ = 8906456688.

The previous prime is 20781732287. The next prime is 20781732341. The reversal of 20781732328 is 82323718702.

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, 185551126 + ... + 185551237.

It is an arithmetic number, because the mean of its divisors is an integer number (2783267730).

Almost surely, 2^20781732328 is an apocalyptic number.

20781732328 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20781732328 is an abundant number, since it is smaller than the sum of its proper divisors (23750551352).

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

20781732328 is a wasteful number, since it uses less digits than its factorization.

20781732328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371102376 (or 371102372 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 43.

The spelling of 20781732328 in words is "twenty billion, seven hundred eighty-one million, seven hundred thirty-two thousand, three hundred twenty-eight".