20535228728 has 32 divisors (see below), whose sum is σ = 46320067200. Its totient is φ = 8337611232.

The previous prime is 20535228689. The next prime is 20535228731. The reversal of 20535228728 is 82782253502.

It is a super-2 number, since 2×20535228728² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9648950 + ... + 9651077.

It is an arithmetic number, because the mean of its divisors is an integer number (1447502100).

Almost surely, 2^20535228728 is an apocalyptic number.

20535228728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20535228728 is an abundant number, since it is smaller than the sum of its proper divisors (25784838472).

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

20535228728 is a wasteful number, since it uses less digits than its factorization.

20535228728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19300059 (or 19300055 counting only the distinct ones).

The product of its (nonzero) digits is 537600, while the sum is 44.

The spelling of 20535228728 in words is "twenty billion, five hundred thirty-five million, two hundred twenty-eight thousand, seven hundred twenty-eight".