20728758 has 8 divisors (see below), whose sum is σ = 41457528. Its totient is φ = 6909584.

The previous prime is 20728733. The next prime is 20728759. The reversal of 20728758 is 85782702.

It is a sphenic number, since it is the product of 3 distinct primes.

20728758 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20728759) 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, 1727391 + ... + 1727402.

It is an arithmetic number, because the mean of its divisors is an integer number (5182191).

Almost surely, 2^20728758 is an apocalyptic number.

20728758 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20728758 is a wasteful number, since it uses less digits than its factorization.

20728758 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3454798.

The product of its (nonzero) digits is 62720, while the sum is 39.

The square root of 20728758 is about 4552.8845801316. The cubic root of 20728758 is about 274.6994313848.

The spelling of 20728758 in words is "twenty million, seven hundred twenty-eight thousand, seven hundred fifty-eight".